https://github.com/guobinhit/myleetcode

♨️ Detailed Java & Go & Python solution of LeetCode.
https://github.com/guobinhit/myleetcode

algorithm interview leetcode list queue search sort stack string tree

Last synced: 2 days ago
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♨️ Detailed Java & Go & Python solution of LeetCode.

• Host: GitHub
• URL: https://github.com/guobinhit/myleetcode
• Owner: guobinhit
• License: mit
• Created: 2018-08-21T23:49:58.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2023-01-09T03:36:45.000Z (almost 2 years ago)
• Last Synced: 2023-03-05T04:28:15.532Z (over 1 year ago)
• Topics: algorithm, interview, leetcode, list, queue, search, sort, stack, string, tree
• Language: Java
• Homepage: https://guobinhit.github.io/myleetcode/
• Size: 1.39 MB
• Stars: 46
• Watchers: 4
• Forks: 28
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

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README

        
# myleetcode

![author](https://img.shields.io/badge/author-chariesgavin-blueviolet.svg)![issues](https://img.shields.io/github/issues/guobinhit/myleetcode.svg)![stars](https://img.shields.io/github/stars/guobinhit/myleetcode.svg)![forks](	https://img.shields.io/github/forks/guobinhit/myleetcode.svg)![license](https://img.shields.io/github/license/guobinhit/myleetcode.svg)

My LeetCode Solutions!

## Contributing

Contributions are very welcome!

If you see an problem that you'd like to see fixed, the best way to make it happen is to help out by submitting a pull request implementing it. Refer to the [CONTRIBUTING.md](https://github.com/guobinhit/myleetcode/blob/master/CONTRIBUTING.md) file for more details about the workflow. 

You can also ask for problem solving ideas and discuss in GitHub issues directly.

## INDEX

- **Learn**

  - [Array and String](#array-and-string)

  - [Queue & Stack](#queue--stack)

  - [Linked List](#linked-list)

  - [Hash Table](#hash-table)

  - [Binary Search](#binary-search)

  - [Binary Tree](#binary-tree)

  - [Binary Search Tree](#binary-search-tree)

  - [N-ary Tree](#n-ary-tree)

  - [Trie (Prefix Tree)](#trie-prefix-tree)

  - [Decision Tree](#decision-tree)

  - [Recursion I](#recursion-i)

  - [Recursion II](#recursion-ii)

  - [Concurrency](#concurrency)

  - [Others](#others)

  - [Shell](#shell)

  - [Database](#database)

  - [Sort Algorithm](#sort-algorithm)

  - [Search Algorithm](#search-algorithm)

- **Interview**

  - [Top Interview Questions](#top-interview-questions)

    - [Easy Collection](#easy-collection)

    - [Medium Collection](#medium-collection)

    - [Hard Collection](#hard-collection)

## Learn

### Array and String

|  #  |      Title     |   Solutions  |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|14|[Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_14.java) & Python|Easy| Introduction to String

|26|[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_26.java) & Python|Easy| Conclusion

|27|[Remove Element](https://leetcode.com/problems/remove-element/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_27.java) & [Go](../master/codes/go/leetcodes/learn/array_and_string/27.go)|Easy| Two-Pointer Technique

|28|[Implement strStr()](https://leetcode.com/problems/implement-strstr/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_28.java) & Python|Easy| Introduction to String

|54|[Spiral Matrix](https://leetcode.com/problems/spiral-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_54.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_54.py)|Medium| Introduction to 2D Array

|66|[Plus One](https://leetcode.com/problems/plus-one/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_66.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_66.py)|Easy| Introduction to Array

|67|[Add Binary](https://leetcode.com/problems/add-binary/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_67.java) & Python|Easy| Introduction to String

|118|[Pascal's Triangle](https://leetcode.com/problems/pascals-triangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_118.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_118.py)| Easy| Introduction to 2D Array

|119|[Pascal's Triangle II](https://leetcode.com/problems/pascals-triangle-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_119.java) & Python| Easy| Conclusion

|151|[Reverse Words in a String](https://leetcode.com/problems/pascals-triangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_151.java) & Python| Medium| Conclusion

|167|[Two Sum II - Input array is sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_167.java) & Python| Easy| Two-Pointer Technique

|189|[Rotate Array](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_189.java) & Python| Easy| Conclusion

|209|[Minimum Size Subarray Sum](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_209.java) & Python| Medium| Two-Pointer Technique

|283|[Move Zeroes](https://leetcode.com/problems/move-zeroes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_283.java) & Python| Easy| Conclusion

|344|[Reverse String](https://leetcode.com/problems/reverse-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_344.java) & Python| Easy| Two-Pointer Technique

|485|[Max Consecutive Ones](https://leetcode.com/problems/diagonal-traverse/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_485.java) & Python |Easy| Two-Pointer Technique

|498|[Diagonal Traverse](https://leetcode.com/problems/diagonal-traverse/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_498.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_498.py) |Medium| Introduction to 2D Array

|557|[Reverse Words in a String III](https://leetcode.com/problems/reverse-words-in-a-string-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_557.java) & Python |Easy| Conclusion

|561|[Array Partition I](https://leetcode.com/problems/array-partition-i/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_561.java)  & Python|Easy| Two-Pointer Technique

|724|[Find Pivot Index](https://leetcode.com/problems/find-pivot-index/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_724.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_724.py)| Easy | Introduction to Array

|747|[Largest Number Greater Than Twice of Others](https://leetcode.com/problems/largest-number-at-least-twice-of-others/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_747.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/array_and_string/_747.py)| Easy| Introduction to Array

### Queue & Stack

|  #  |      Title     |   Solutions   |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|20|[Valid Parentheses](https://leetcode.com/problems/valid-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_20.java) & Python|Easy| Stack: Last-in-first-out Data Structure

|133|[Clone Graph](https://leetcode.com/problems/clone-graph/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_133.java) & Python|Medium| Stack and DFS

|150|[Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_150.java) & Python|Medium| Stack: Last-in-first-out Data Structure

|155|[Min Stack](https://leetcode.com/problems/min-stack/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_155.java) & Python|Easy| Stack: Last-in-first-out Data Structure

|200|[Number of Islands](https://leetcode.com/problems/number-of-islands/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_200.java) & Python|Medium| Queue and BFS

|225|[Implement Stack using Queues](https://leetcode.com/problems/implement-stack-using-queues/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_225.java) & Python|Easy| Conclusion

|232|[Implement Queue using Stacks](https://leetcode.com/problems/implement-queue-using-stacks/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_232.java) & Python|Easy| Conclusion

|279|[Perfect Squares](https://leetcode.com/problems/perfect-squares/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_279.java) & Python|Medium| Queue and BFS

|394|[Decode String](https://leetcode.com/problems/decode-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_394.java) & Python|Medium| Conclusion

|494|[Target Sum](https://leetcode.com/problems/target-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_494.java) & Python|Medium| Stack and DFS

|542|[01 Matrix](https://leetcode.com/problems/01-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_542.java) & Python|Medium| Conclusion

|622|[Design Circular Queue](https://leetcode.com/problems/longest-common-prefix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_622.java) & Python|Medium| Queue: First-in-first-out Data Structure

|733|[Flood Fill](https://leetcode.com/problems/flood-fill/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_733.java) & Python|Easy| Conclusion

|739|[Daily Temperatures](https://leetcode.com/problems/daily-temperatures/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_739.java) & Python|Medium| Stack: Last-in-first-out Data Structure

|752|[Open the Lock](https://leetcode.com/problems/open-the-lock/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_752.java) & Python|Medium| Queue and BFS

|841|[Keys and Rooms](https://leetcode.com/problems/keys-and-rooms/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_841.java) & Python|Medium| Conclusion

### Linked List

|  #  |      Title     |   Solutions  |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_2.java) & Python|Medium| Conclusion

|19|[Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_19.java) & Python|Medium| Two Pointer Technique

|21|[Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_21.java) & Python|Easy| Conclusion

|61|[Rotate List](https://leetcode.com/problems/rotate-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_61.java) & Python|Medium| Conclusion

|135|[Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_135.java) & Python|Medium| Conclusion

|141|[Linked List Cycle](https://leetcode.com/problems/number-of-islands/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_141.java) & Python|Easy| Two Pointer Technique

|142|[Linked List Cycle II](https://leetcode.com/problems/linked-list-cycle-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_142.java) & Python|Medium| Two Pointer Technique

|160|[Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_160.java) & Python|Easy| Two Pointer Technique

|203|[Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_203.java) & Python|Easy| Classic Problems

|206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_206.java) & Python|Easy| Classic Problems

|234|[Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_234.java) & Python|Easy| Classic Problems

|328|[Odd Even Linked List](https://leetcode.com/problems/odd-even-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_328.java) & Python|Medium| Classic Problems

|430|[Flatten a Multilevel Doubly Linked List](https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_430.java) & Python|Medium| Conclusion

|707|[Design Linked List](https://leetcode.com/problems/number-of-islands/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_707.java) & Python|Easy| Singly Linked List

### Hash Table

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|1|[Two Sum](https://leetcode.com/problems/two-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_1.java) & Python |Easy| Practical Application - Hash Map

|3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_3.java) & Python |Medium| Conclusion

|36|[Valid Sudoku](https://leetcode.com/problems/valid-sudoku/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_36.java) & Python |Medium| Practical Application - Design the Key

|49|[Group Anagrams](https://leetcode.com/problems/group-anagrams/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_49.java) & Python |Medium| Practical Application - Design the Key

|136|[Single Number](https://leetcode.com/problems/single-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_136.java) & Python |Easy| Practical Application - Hash Set

|202|[Happy Number](https://leetcode.com/problems/happy-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_202.java) & Python |Easy| Practical Application - Hash Set

|205|[Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_205.java) & Python |Easy| Practical Application - Hash Map

|217|[Contains Duplicate](https://leetcode.com/problems/contains-duplicate/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_217.java) & Python |Easy| Practical Application - Hash Set

|219|[Contains Duplicate II](https://leetcode.com/problems/contains-duplicate-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_219.java) & Python |Easy| Practical Application - Hash Map

|347|[Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_347.java) & Python |Medium| Conclusion

|349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_349.java) & Python |Easy| Practical Application - Hash Set

|350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_350.java) & Python |Easy| Practical Application - Hash Map

|380|[Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_380.java) & Python |Medium| Conclusion

|387|[First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_387.java) & Python |Easy| Practical Application - Hash Map

|454|[4Sum II](https://leetcode.com/problems/4sum-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_454.java) & Python |Medium| Conclusion

|599|[Minimum Index Sum of Two Lists](https://leetcode.com/problems/minimum-index-sum-of-two-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_599.java) & Python |Easy| Practical Application - Hash Map

|652|[Find Duplicate Subtrees](https://leetcode.com/problems/find-duplicate-subtrees/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_652.java) & Python |Medium| Practical Application - Design the Key

|705|[Design HashSet](https://leetcode.com/problems/design-hashset/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_705.java) & Python |Easy| Design a Hash Table

|706|[Design HashMap](https://leetcode.com/problems/design-hashmap/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_706.java) & Python |Easy| Design a Hash Table

|771|[Jewels and Stones](https://leetcode.com/problems/jewels-and-stones/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_771.java) & Python |Easy| Conclusion

### Binary Search

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_4.java) & Python |Hard| More Practices II

|33|[Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_33.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_33.py)|Medium| Template I

|34|[Find First and Last Position of Element in Sorted Array](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_34.java) & Python |Medium| Template III

|50|[Pow(x, n)](https://leetcode.com/problems/powx-n/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_50.java) & Python |Medium| Conclusion

|69|[Sqrt(x)](https://leetcode.com/problems/sqrtx/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_69.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_69.py)|Easy| Template I

|153|[Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_153.java) & Python|Medium| Template II

|154|[Find Minimum in Rotated Sorted Array II](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_154.java) & Python| Hard| More Practices

|162|[Find Peak Element](https://leetcode.com/problems/find-peak-element/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_162.java) & Python|Medium| Template II

|167|[Two Sum II - Input array is sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_167.java) & Python |Easy| More Practices

|278|[First Bad Version](https://leetcode.com/problems/first-bad-version/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_278.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_278.py)|Easy| Template II

|287|[Find the Duplicate Number](https://leetcode.com/problems/find-the-duplicate-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_287.java) & Python |Medium| More Practices II

|349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_349.java) & Python |Easy| More Practices

|350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_350.java) & Python |Easy| More Practices

|367|[Valid Perfect Square](https://leetcode.com/problems/valid-perfect-square/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_367.java) & Python |Easy| Conclusion

|374|[Guess Number Higher or Lower](https://leetcode.com/problems/guess-number-higher-or-lower/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_374.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_374.py)|Easy| Template I

|410|[Split Array Largest Sum](https://leetcode.com/problems/split-array-largest-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_410.java) & Python |Hard| More Practices II

|658|[Find K Closest Elements](https://leetcode.com/problems/find-k-closest-elements/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_658.java) & Python |Medium| Template III

|704|[Binary Search](https://leetcode.com/problems/binary-search/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_704.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_704.py)|Easy| Background

|719|[Find K-th Smallest Pair Distance](https://leetcode.com/problems/find-k-th-smallest-pair-distance/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_719.java) & Python |Hard| More Practices II

|744|[Find Smallest Letter Greater Than Target](https://leetcode.com/problems/find-smallest-letter-greater-than-target/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_744.java) & Python|Easy| Conclusion

### Binary Tree

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|94|[Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_94.java) & Python |Medium| Traverse A Tree

|101|[Symmetric Tree](https://leetcode.com/problems/symmetric-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_101.java) & Python |Easy| Solve Tree Problems Recursively

|102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_102.java) & Python |Medium| Traverse A Tree

|104|[Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_104.java) & Python |Easy| Solve Tree Problems Recursively

|105|[Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_105.java) & Python |Medium| Conclusion

|106|[Construct Binary Tree from Inorder and Postorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_106.java) & Python |Medium| Conclusion

|112|[Path Sum](https://leetcode.com/problems/path-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_112.java) & Python |Easy| Solve Tree Problems Recursively

|116|[Populating Next Right Pointers in Each Node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_116.java) & Python |Medium| Conclusion

|117|[Populating Next Right Pointers in Each Node II](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_117.java) & Python |Medium| Conclusion

|144|[Binary Tree Preorder Traversal](https://leetcode.com/problems/binary-tree-preorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_144.java) & Python |Medium| Traverse A Tree

|145|[Binary Tree Postorder Traversal](https://leetcode.com/problems/binary-tree-postorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_145.java) & Python |Hard| Traverse A Tree

|236|[Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_236.java) & Python |Medium| Conclusion

|297|[Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_297.java) & Python |Medium| Conclusion

### Binary Search Tree

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|98|[Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_98.java) & Python |Medium| Introduction to BST

|108|[Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_108.java) & Python |Easy| Appendix: Height-balanced BST

|110|[Balanced Binary Tree](https://leetcode.com/problems/balanced-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_110.java) & Python |Easy| Appendix: Height-balanced BST

|173|[Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_173.java) & Python |Medium| Introduction to BST

|220|[Contains Duplicate III](https://leetcode.com/problems/contains-duplicate-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_220.java) & Python |Medium| Conclusion

|235|[Lowest Common Ancestor of a Binary Search Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_235.java) & Python |Easy| Conclusion

|450|[Delete Node in a BST](https://leetcode.com/problems/delete-node-in-a-bst/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_450.java) & Python |Medium| Basic Operations in BST

|700|[Search in a Binary Search Tree](https://leetcode.com/problems/search-in-a-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_700.java) & Python |Easy| Basic Operations in BST

|701|[Insert into a Binary Search Tree](https://leetcode.com/problems/insert-into-a-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_701.java) & Python |Medium| Basic Operations in BST

|703|[Kth Largest Element in a Stream](https://leetcode.com/problems/kth-largest-element-in-a-stream/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_703.java) & Python |Easy| Conclusion

### N-ary Tree

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|429|[N-ary Tree Level Order Traversal](https://leetcode.com/problems/n-ary-tree-level-order-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/n_ary_tree/_429.java) & Python |Easy| Traversal

|559|[Maximum Depth of N-ary Tree](https://leetcode.com/problems/maximum-depth-of-n-ary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/n_ary_tree/_559.java) & Python |Easy| Recursion

|589|[N-ary Tree Preorder Traversal](https://leetcode.com/problems/n-ary-tree-preorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/n_ary_tree/_589.java) & Python |Easy| Traversal

|590|[N-ary Tree Postorder Traversal](https://leetcode.com/problems/n-ary-tree-postorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/n_ary_tree/_590.java) & Python |Easy| Traversal

### Trie (Prefix Tree)

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|208|[Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_208.java) & Python |Medium| Basic Operations

|211|[Add and Search Word - Data structure design](https://leetcode.com/problems/add-and-search-word-data-structure-design/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_211.java) & Python |Medium| Practical Application I

|212|[Word Search II](https://leetcode.com/problems/word-search-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_212.java) & Python |Hard| Practical Application II

|336|[Palindrome Pairs](https://leetcode.com/problems/palindrome-pairs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_336.java) & Python |Hard| Practical Application II

|421|[Maximum XOR of Two Numbers in an Array](https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_421.java) & Python |Medium| Practical Application II

|648|[Replace Words](https://leetcode.com/problems/replace-words/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_648.java) & Python |Medium| Practical Application I

|677|[Map Sum Pairs](https://leetcode.com/problems/map-sum-pairs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_677.java) & Python |Medium| Practical Application I

### Decision Tree

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

| ### |[Calculate Entropy](https://leetcode.com/explore/learn/card/decision-tree/285/implementation/2650/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/decision_tree/CalculateEntropy.java) & Python |Easy| Implementation

| ### |[Calculate Maximum Information Gain](https://leetcode.com/explore/learn/card/decision-tree/285/implementation/2651/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/decision_tree/CalculateMaxInfoGain.java) & Python |Easy| Implementation

### Recursion I

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|21|[Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_21.java) & Python|Easy| Conclusion

|24|[Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_i/_24.java) & Python| Medium| Principle of Recursion

|50|[Pow(x, n)](https://leetcode.com/problems/powx-n/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_50.java) & Python |Medium| Complexity Analysis

|70|[Climbing Stairs](https://leetcode.com/problems/climbing-stairs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_70.java) & Python| Easy| Memoization

|95|[Unique Binary Search Trees II](https://leetcode.com/problems/unique-binary-search-trees-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_95.java) & Python|Medium| Conclusion

|104|[Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_104.java) & Python |Easy| Complexity Analysis

|118|[Pascal's Triangle](https://leetcode.com/problems/pascals-triangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_118.java) & Python| Easy| Recurrence Relation

|119|[Pascal's Triangle II](https://leetcode.com/problems/pascals-triangle-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_119.java) & Python| Easy| Recurrence Relation

|206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_206.java) & Python|Easy| Recurrence Relation

|344|[Reverse String](https://leetcode.com/problems/reverse-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_344.java) & Python| Easy| Principle of Recursion

|509|[Fibonacci Number](https://leetcode.com/problems/fibonacci-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_509.java) & Python| Easy| Memoization

|779|[K-th Symbol in Grammar](https://leetcode.com/problems/k-th-symbol-in-grammar/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_779.java) & Python|Medium| Conclusion

### Recursion II

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|17|[Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_17.java) & Python |Medium| Conclusion

|22|[Generate Parentheses](https://leetcode.com/problems/generate-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_22.java) & Python |Medium| Recursion to Iteration

|37|[Sudoku Solver](https://leetcode.com/problems/sudoku-solver/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_37.java) & Python |Hard| Backtracking

|46|[Permutations](https://leetcode.com/problems/permutations/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_46.java) & Python |Medium| Conclusion

|52|[N-Queens II](https://leetcode.com/problems/n-queens-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_52.java) & Python |Hard| Backtracking

|77|[Combinations](https://leetcode.com/problems/combinations/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_77.java) & Python |Medium| Backtracking

|84|[Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_84.java) & Python |Hard| Conclusion

|94|[Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_94.java) & Python |Medium| Recursion to Iteration

|98|[Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_98.java) & Python |Medium| Divide and Conquer

|100|[Same Tree](https://leetcode.com/problems/same-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_100.java) & Python |Easy| Recursion to Iteration

|102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_102.java) & Python |Medium| Recursion to Iteration

|218|[The Skyline Problem](https://leetcode.com/problems/the-skyline-problem/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_218.java) & Python |Hard| Conclusion

|240|[Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_240.java) & Python |Medium| Divide and Conquer

|912|[Sort an Array](https://leetcode.com/problems/sort-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_912.java) & Python|Medium| Divide and Conquer

### Concurrency

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|1114|[Print in Order](https://leetcode.com/problems/print-in-order/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1114.java) & Python |Easy| Concurrency

|1115|[Print FooBar Alternately](https://leetcode.com/problems/print-foobar-alternately/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1115.java) & Python |Medium| Concurrency

|1116|[Print Zero Even Odd](https://leetcode.com/problems/print-zero-even-odd/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1116.java) & Python |Medium| Concurrency

|1117|[Building H2O](https://leetcode.com/problems/building-h2o/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1117.java) & Python |Medium| Concurrency

|1195|[Fizz Buzz Multithreaded](https://leetcode.com/problems/fizz-buzz-multithreaded/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1195.java) & Python |Medium| Concurrency

|1226|[The Dining Philosophers](https://leetcode.com/problems/the-dining-philosophers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/concurrency/_1226.java) & Python |Medium| Concurrency

### Others

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|6|[ZigZag Conversion](https://leetcode.com/problems/zigzag-conversion/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_6.java) & Python |Medium| Others

|9|[Palindrome Number](https://leetcode.com/problems/palindrome-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_9.java) & Python |Easy| Others

|12|[Integer to Roman](https://leetcode.com/problems/integer-to-roman/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_12.java) & Python |Medium| Others

|16|[3Sum Closest](https://leetcode.com/problems/3sum-closest/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_16.java) & Python |Medium| Others

|18|[4Sum](https://leetcode.com/problems/4sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_18.java) & Python |Medium| Others

|25|[Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_25.java) & Python |Hard| Others

|30|[Substring with Concatenation of All Words](https://leetcode.com/problems/substring-with-concatenation-of-all-words/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_30.java) & Python |Hard| Others

|31|[Next Permutation](https://leetcode.com/problems/next-permutation/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_31.java) & Python |Medium| Others

|32|[Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_32.java) & Python |Hard| Others

|35|[Search Insert Position](https://leetcode.com/problems/search-insert-position/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_35.java) & Python |Easy| Others

|39|[Combination Sum](https://leetcode.com/problems/combination-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_39.java) & Python |Medium| Others

|40|[Combination Sum II](https://leetcode.com/problems/combination-sum-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_40.java) & Python |Medium| Others

|43|[Multiply Strings](https://leetcode.com/problems/multiply-strings/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_43.java) & Python |Medium| Others

|45|[Jump Game II](https://leetcode.com/problems/jump-game-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_45.java) & Python |Hard| Others

|47|[Permutations II](https://leetcode.com/problems/permutations-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_47.java) & Python |Medium| Others

|51|[N-Queens](https://leetcode.com/problems/n-queens/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_51.java) & Python |Hard| Others

|57|[Insert Interval](https://leetcode.com/problems/insert-interval/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_57.java) & Python |Hard| Others

|58|[Length of Last Word](https://leetcode.com/problems/length-of-last-word/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_58.java) & Python |Easy| Others

|59|[Spiral Matrix II](https://leetcode.com/problems/spiral-matrix-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_59.java) & Python |Medium| Others

|60|[Permutation Sequence](https://leetcode.com/problems/permutation-sequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_60.java) & Python |Medium| Others

|63|[Unique Paths II](https://leetcode.com/problems/unique-paths-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_63.java) & Python |Medium| Others

|64|[Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_64.java) & Python |Medium| Others

|65|[Valid Number](https://leetcode.com/problems/valid-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_65.java) & Python |Hard| Others

|68|[Text Justification](https://leetcode.com/problems/text-justification/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_68.java) & Python |Hard| Others

|71|[Simplify Path](https://leetcode.com/problems/simplify-path/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_71.java) & Python |Medium| Others

|72|[Edit Distance](https://leetcode.com/problems/edit-distance/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_72.java) & Python |Hard| Others

|74|[Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_74.java) & Python |Medium| Others

|80|[Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_80.java) & Python |Medium| Others

|81|[Search in Rotated Sorted Array II](https://leetcode.com/problems/search-in-rotated-sorted-array-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_81.java) & Python |Medium| Others

|82|[Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_82.java) & Python |Medium| Others

|83|[Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_83.java) & Python |Easy| Others

|85|[Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_85.java) & Python |Hard| Others

|86|[Partition List](https://leetcode.com/problems/partition-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_86.java) & Python |Medium| Others

|87|[Scramble String](https://leetcode.com/problems/scramble-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_87.java) & Python |Hard| Others

|89|[Gray Code](https://leetcode.com/problems/gray-code/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_89.java) & Python |Medium| Others

|90|[Subsets II](https://leetcode.com/problems/subsets-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_90.java) & Python |Medium| Others

|92|[Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_92.java) & Python |Medium| Others

|93|[Restore IP Addresses](https://leetcode.com/problems/restore-ip-addresses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_93.java) & Python |Medium| Others

|96|[Unique Binary Search Trees](https://leetcode.com/problems/unique-binary-search-trees/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_96.java) & Python |Medium| Others

|97|[Interleaving String](https://leetcode.com/problems/interleaving-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_97.java) & Python |Hard| Others

|99|[Recover Binary Search Tree](https://leetcode.com/problems/recover-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_99.java) & Python |Hard| Others

|107|[Binary Tree Level Order Traversal II](https://leetcode.com/problems/binary-tree-level-order-traversal-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_107.java) & Python |Easy| Others

|109|[Convert Sorted List to Binary Search Tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_109.java) & Python |Medium| Others

|111|[Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_111.java) & Python |Easy| Others

|113|[Path Sum II](https://leetcode.com/problems/path-sum-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_113.java) & Python |Medium| Others

|114|[Flatten Binary Tree to Linked List](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_114.java) & Python |Medium| Others

|115|[Distinct Subsequences](https://leetcode.com/problems/distinct-subsequences/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_115.java) & Python |Hard| Others

|120|[Triangle](https://leetcode.com/problems/triangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_120.java) & Python |Medium| Others

|123|[Best Time to Buy and Sell Stock III](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_123.java) & Python |Hard| Others

|126|[Word Ladder II](https://leetcode.com/problems/word-ladder-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_126.java) & Python |Hard| Others

|129|[Sum Root to Leaf Numbers](https://leetcode.com/problems/sum-root-to-leaf-numbers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_129.java) & Python |Medium| Others

|132|[Palindrome Partitioning II](https://leetcode.com/problems/palindrome-partitioning-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_132.java) & Python |Hard| Others

|134|[Gas Station](https://leetcode.com/problems/gas-station/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_134.java) & Python |Medium| Others

|135|[Candy](https://leetcode.com/problems/candy/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_135.java) & Python |Hard| Others

|137|[Single Number II](https://leetcode.com/problems/single-number-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_137.java) & Python |Medium| Others

|143|[Reorder List](https://leetcode.com/problems/reorder-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_143.java) & Python |Medium| Others

|147|[Insertion Sort List](https://leetcode.com/problems/insertion-sort-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_147.java) & Python |Medium| Others

|164|[Maximum Gap](https://leetcode.com/problems/maximum-gap/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_164.java) & Python |Hard| Others

|165|[Compare Version Numbers](https://leetcode.com/problems/compare-version-numbers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_165.java) & Python |Medium| Others

|168|[Excel Sheet Column Title](https://leetcode.com/problems/excel-sheet-column-title/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_168.java) & Python |Easy| Others

|174|[Dungeon Game](https://leetcode.com/problems/dungeon-game/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_174.java) & Python |Hard| Others

|187|[Repeated DNA Sequences](https://leetcode.com/problems/repeated-dna-sequences/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_187.java) & Python |Medium| Others

|188|[Best Time to Buy and Sell Stock IV](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_188.java) & Python |Hard| Others

|199|[Binary Tree Right Side View](https://leetcode.com/problems/binary-tree-right-side-view/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_199.java) & Python |Medium| Others

|201|[Bitwise AND of Numbers Range](https://leetcode.com/problems/bitwise-and-of-numbers-range/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_201.java) & Python |Medium| Others

|213|[House Robber II](https://leetcode.com/problems/house-robber-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_213.java) & Python |Medium| Others

|214|[Shortest Palindrome](https://leetcode.com/problems/shortest-palindrome/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_214.java) & Python |Hard| Others

|216|[Combination Sum III](https://leetcode.com/problems/combination-sum-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_216.java) & Python |Medium| Others

|221|[Maximal Square](https://leetcode.com/problems/maximal-square/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_221.java) & Python |Medium| Others

|222|[Count Complete Tree Nodes](https://leetcode.com/problems/count-complete-tree-nodes/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_222.java) & Python |Medium| Others

|223|[Rectangle Area](https://leetcode.com/problems/rectangle-area/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_223.java) & Python |Medium| Others

|224|[Basic Calculator](https://leetcode.com/problems/basic-calculator/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_224.java) & Python |Hard| Others

|226|[Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_226.java) & Python |Easy| Others

|228|[Summary Ranges](https://leetcode.com/problems/summary-ranges/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_228.java) & Python |Medium| Others

|229|[Majority Element II](https://leetcode.com/problems/majority-element-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_229.java) & Python |Medium| Others

|231|[Power of Two](https://leetcode.com/problems/power-of-two/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_231.java) & Python |Easy| Others

|233|[Number of Digit One](https://leetcode.com/problems/number-of-digit-one/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_233.java) & Python |Hard| Others

|241|[Different Ways to Add Parentheses](https://leetcode.com/problems/different-ways-to-add-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_241.java) & Python |Medium| Others

|257|[Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_257.java) & Python |Easy| Others

|258|[Add Digits](https://leetcode.com/problems/add-digits/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_258.java) & Python |Easy| Others

|260|[Single Number III](https://leetcode.com/problems/single-number-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_260.java) & Python |Medium| Others

|263|[Ugly Number](https://leetcode.com/problems/ugly-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_263.java) & Python |Easy| Others

|264|[Ugly Number II](https://leetcode.com/problems/ugly-number-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_264.java) & Python |Medium| Others

|273|[Integer to English Words](https://leetcode.com/problems/integer-to-english-words/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_273.java) & Python |Hard| Others

|274|[H-Index](https://leetcode.com/problems/h-index/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_274.java) & Python |Medium| Others

|275|[H-Index II](https://leetcode.com/problems/h-index-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_275.java) & Python |Medium| Others

|282|[Expression Add Operators](https://leetcode.com/problems/expression-add-operators/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_282.java) & Python |Hard| Others

|284|[Peeking Iterator](https://leetcode.com/problems/peeking-iterator/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_284.java) & Python |Medium| Others

|290|[Word Pattern](https://leetcode.com/problems/word-pattern/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_290.java) & Python |Easy| Others

|292|[Nim Game](https://leetcode.com/problems/nim-game/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_292.java) & Python |Easy| Others

|299|[Bulls and Cows](https://leetcode.com/problems/bulls-and-cows/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_299.java) & Python |Easy| Others

|303|[Range Sum Query - Immutable](https://leetcode.com/problems/range-sum-query-immutable/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_303.java) & Python |Easy| Others

|304|[Range Sum Query 2D - Immutable](https://leetcode.com/problems/range-sum-query-2d-immutable/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_304.java) & Python |Medium| Others

|306|[Additive Number](https://leetcode.com/problems/additive-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_306.java) & Python |Medium| Others

|307|[Range Sum Query - Mutable](https://leetcode.com/problems/range-sum-query-mutable/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_307.java) & Python |Medium| Others

|310|[Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_310.java) & Python |Medium| Others

|313|[Super Ugly Number](https://leetcode.com/problems/super-ugly-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_313.java) & Python |Medium| Others

|316|[Remove Duplicate Letters](https://leetcode.com/problems/remove-duplicate-letters/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_316.java) & Python |Hard| Others

|318|[Maximum Product of Word Lengths](https://leetcode.com/problems/maximum-product-of-word-lengths/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_318.java) & Python |Medium| Others

|319|[Bulb Switcher](https://leetcode.com/problems/bulb-switcher/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_319.java) & Python |Medium| Others

|321|[Create Maximum Number](https://leetcode.com/problems/create-maximum-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_321.java) & Python |Hard| Others

|327|[Count of Range Sum](https://leetcode.com/problems/count-of-range-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_327.java) & Python |Hard| Others

|330|[Patching Array](https://leetcode.com/problems/patching-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_330.java) & Python |Hard| Others

|331|[Verify Preorder Serialization of a Binary Tree](https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_331.java) & Python |Medium| Others

|332|[Reconstruct Itinerary](https://leetcode.com/problems/reconstruct-itinerary/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_332.java) & Python |Medium| Others

|335|[Self Crossing](https://leetcode.com/problems/self-crossing/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_335.java) & Python |Hard| Others

|337|[House Robber III](https://leetcode.com/problems/house-robber-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_337.java) & Python |Medium| Others

|338|[Counting Bits](https://leetcode.com/problems/counting-bits/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_338.java) & Python |Medium| Others

|342|[Power of Four](https://leetcode.com/problems/power-of-four/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_342.java) & Python |Easy| Others

|343|[Integer Break](https://leetcode.com/problems/integer-break/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_343.java) & Python |Medium| Others

|345|[Reverse Vowels of a String](https://leetcode.com/problems/reverse-vowels-of-a-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_345.java) & Python |Easy| Others

|352|[Data Stream as Disjoint Intervals](https://leetcode.com/problems/data-stream-as-disjoint-intervals/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_352.java) & Python |Hard| Others

|354|[Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_354.java) & Python |Hard| Others

|355|[Design Twitter](https://leetcode.com/problems/design-twitter/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_355.java) & Python |Medium| Others

|357|[Count Numbers with Unique Digits](https://leetcode.com/problems/count-numbers-with-unique-digits/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_357.java) & Python |Medium| Others

|363|[Max Sum of Rectangle No Larger Than K](https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_363.java) & Python |Hard| Others

|365|[Water and Jug Problem](https://leetcode.com/problems/water-and-jug-problem/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_365.java) & Python |Medium| Others

|368|[Largest Divisible Subset](https://leetcode.com/problems/largest-divisible-subset/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_368.java) & Python |Medium| Others

|372|[Super Pow](https://leetcode.com/problems/super-pow/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_372.java) & Python |Medium| Others

|373|[Find K Pairs with Smallest Sums](https://leetcode.com/problems/find-k-pairs-with-smallest-sums/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_373.java) & Python |Medium| Others

|375|[Guess Number Higher or Lower II](https://leetcode.com/problems/guess-number-higher-or-lower-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_375.java) & Python |Medium| Others

|376|[Wiggle Subsequence](https://leetcode.com/problems/wiggle-subsequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_376.java) & Python |Medium| Others

|377|[Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_377.java) & Python |Medium| Others

|381|[Insert Delete GetRandom O(1) - Duplicates allowed](https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_381.java) & Python |Hard| Others

|382|[Linked List Random Node](https://leetcode.com/problems/linked-list-random-node/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_382.java) & Python |Medium| Others

|383|[Ransom Note](https://leetcode.com/problems/ransom-note/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_383.java) & Python |Easy| Others

|385|[Mini Parser](https://leetcode.com/problems/mini-parser/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_385.java) & Python |Medium| Others

|386|[Lexicographical Numbers](https://leetcode.com/problems/lexicographical-numbers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_386.java) & Python |Medium| Others

|388|[Longest Absolute File Path](https://leetcode.com/problems/longest-absolute-file-path/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_388.java) & Python |Medium| Others

|389|[Find the Difference](https://leetcode.com/problems/find-the-difference/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_389.java) & Python |Easy| Others

|390|[Elimination Game](https://leetcode.com/problems/elimination-game/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_390.java) & Python |Medium| Others

|391|[Perfect Rectangle](https://leetcode.com/problems/perfect-rectangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_391.java) & Python |Hard| Others

|392|[Is Subsequence](https://leetcode.com/problems/is-subsequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_392.java) & Python |Easy| Others

|393|[UTF-8 Validation](https://leetcode.com/problems/utf-8-validation/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_393.java) & Python |Medium| Others

|395|[Longest Substring with At Least K Repeating Characters](https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_395.java) & Python |Medium| Others

|396|[Rotate Function](https://leetcode.com/problems/rotate-function/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_396.java) & Python |Medium| Others

|397|[Integer Replacement](https://leetcode.com/problems/integer-replacement/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_397.java) & Python |Medium| Others

|398|[Random Pick Index](https://leetcode.com/problems/random-pick-index/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_398.java) & Python |Medium| Others

|399|[Evaluate Division](https://leetcode.com/problems/evaluate-division/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_399.java) & Python |Medium| Others

|400|[Nth Digit](https://leetcode.com/problems/nth-digit/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_400.java) & Python |Medium| Others

|401|[Binary Watch](https://leetcode.com/problems/binary-watch/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_401.java) & Python |Easy| Others

|402|[Remove K Digits](https://leetcode.com/problems/remove-k-digits/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_402.java) & Python |Medium| Others

|403|[Frog Jump](https://leetcode.com/problems/frog-jump/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_403.java) & Python |Hard| Others

|404|[Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_404.java) & Python |Easy| Others

|405|[Convert a Number to Hexadecimal](https://leetcode.com/problems/convert-a-number-to-hexadecimal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_405.java) & Python |Easy| Others

|407|[Trapping Rain Water II](https://leetcode.com/problems/trapping-rain-water-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_407.java) & Python |Hard| Others

|409|[Longest Palindrome](https://leetcode.com/problems/longest-palindrome/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_409.java) & Python |Easy| Others

|413|[Arithmetic Slices](https://leetcode.com/problems/arithmetic-slices/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_413.java) & Python |Medium| Others

|414|[Third Maximum Number](https://leetcode.com/problems/third-maximum-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_414.java) & Python |Easy| Others

|415|[Add Strings](https://leetcode.com/problems/add-strings/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_415.java) & Python |Easy| Others

|416|[Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_416.java) & Python |Medium| Others

|417|[Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_417.java) & Python |Medium| Others

|419|[Battleships in a Board](https://leetcode.com/problems/battleships-in-a-board/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_419.java) & Python |Medium| Others

|420|[Strong Password Checker](https://leetcode.com/problems/strong-password-checker/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_420.java) & Python |Hard| Others

|423|[Reconstruct Original Digits from English](https://leetcode.com/problems/reconstruct-original-digits-from-english/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_423.java) & Python |Medium| Others

|424|[Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_424.java) & Python |Medium| Others

|427|[Construct Quad Tree](https://leetcode.com/problems/construct-quad-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_427.java) & Python |Medium| Others

|432|[All O\`one Data Structure](https://leetcode.com/problems/all-oone-data-structure/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_432.java) & Python |Hard| Others

|433|[Minimum Genetic Mutation](https://leetcode.com/problems/minimum-genetic-mutation/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_433.java) & Python |Medium| Others

|434|[Number of Segments in a String](https://leetcode.com/problems/number-of-segments-in-a-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_434.java) & Python |Easy| Others

|435|[Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_435.java) & Python |Medium| Others

|436|[Find Right Interval](https://leetcode.com/problems/find-right-interval/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_436.java) & Python |Medium| Others

|437|[Path Sum III](https://leetcode.com/problems/path-sum-iii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_437.java) & Python |Easy| Others

|438|[Find All Anagrams in a String](https://leetcode.com/problems/find-all-anagrams-in-a-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_438.java) & Python |Medium| Others

|440|[K-th Smallest in Lexicographical Order](https://leetcode.com/problems/k-th-smallest-in-lexicographical-order/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_440.java) & Python |Hard| Others

|441|[Arranging Coins](https://leetcode.com/problems/arranging-coins/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_441.java) & Python |Easy| Others

|442|[Find All Duplicates in an Array](https://leetcode.com/problems/find-all-duplicates-in-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_442.java) & Python |Medium| Others

|443|[String Compression](https://leetcode.com/problems/string-compression/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_443.java) & Python |Easy| Others

|445|[Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_445.java) & Python |Medium| Others

|446|[Arithmetic Slices II - Subsequence](https://leetcode.com/problems/arithmetic-slices-ii-subsequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_446.java) & Python |Hard| Others

|447|[Number of Boomerangs](https://leetcode.com/problems/number-of-boomerangs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_447.java) & Python |Easy| Others

|448|[Find All Numbers Disappeared in an Array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_448.java) & Python |Easy| Others

|449|[Serialize and Deserialize BST](https://leetcode.com/problems/serialize-and-deserialize-bst/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_449.java) & Python |Medium| Others

|451|[Sort Characters By Frequency](https://leetcode.com/problems/sort-characters-by-frequency/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_451.java) & Python |Medium| Others

|452|[Minimum Number of Arrows to Burst Balloons](https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_452.java) & Python |Medium| Others

|453|[Minimum Moves to Equal Array Elements](https://leetcode.com/problems/minimum-moves-to-equal-array-elements/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_453.java) & Python |Easy| Others

|455|[Assign Cookies](https://leetcode.com/problems/assign-cookies/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_455.java) & Python |Easy| Others

|456|[132 Pattern](https://leetcode.com/problems/132-pattern/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_456.java) & Python |Medium| Others

|457|[Circular Array Loop](https://leetcode.com/problems/circular-array-loop/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_457.java) & Python |Medium| Others

|458|[Poor Pigs](https://leetcode.com/problems/poor-pigs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_458.java) & Python |Hard| Others

|459|[Repeated Substring Pattern](https://leetcode.com/problems/repeated-substring-pattern/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_459.java) & Python |Easy| Others

|460|[LFU Cache](https://leetcode.com/problems/lfu-cache/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_460.java) & Python |Hard| Others

|462|[Minimum Moves to Equal Array Elements II](https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_462.java) & Python |Medium| Others

|463|[Island Perimeter](https://leetcode.com/problems/island-perimeter/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_463.java) & Python |Easy| Others

|464|[Can I Win](https://leetcode.com/problems/can-i-win/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_464.java) & Python |Medium| Others

|466|[Count The Repetitions](https://leetcode.com/problems/count-the-repetitions/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_466.java) & Python |Hard| Others

|467|[Unique Substrings in Wraparound String](https://leetcode.com/problems/unique-substrings-in-wraparound-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_467.java) & Python |Medium| Others

|468|[Validate IP Address](https://leetcode.com/problems/validate-ip-address/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_468.java) & Python |Medium| Others

|470|[Implement Rand10() Using Rand7()](https://leetcode.com/problems/implement-rand10-using-rand7/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_470.java) & Python |Medium| Others

|472|[Concatenated Words](https://leetcode.com/problems/concatenated-words/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_472.java) & Python |Hard| Others

|473|[Matchsticks to Square](https://leetcode.com/problems/matchsticks-to-square/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_473.java) & Python |Medium| Others

|474|[Ones and Zeroes](https://leetcode.com/problems/ones-and-zeroes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_474.java) & Python |Medium| Others

|475|[Heaters](https://leetcode.com/problems/heaters/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_475.java) & Python |Easy| Others

|476|[Number Complement](https://leetcode.com/problems/number-complement/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_476.java) & Python |Easy| Others

|477|[Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_477.java) & Python |Medium| Others

|478|[Generate Random Point in a Circle](https://leetcode.com/problems/generate-random-point-in-a-circle/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_478.java) & Python |Medium| Others

|479|[Largest Palindrome Product](https://leetcode.com/problems/largest-palindrome-product/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_479.java) & Python |Hard| Others

|480|[Sliding Window Median](https://leetcode.com/problems/sliding-window-median/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_480.java) & Python |Hard| Others

|481|[Magical String](https://leetcode.com/problems/magical-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_481.java) & Python |Medium| Others

|482|[License Key Formatting](https://leetcode.com/problems/license-key-formatting/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_482.java) & Python |Easy| Others

|483|[Smallest Good Base](https://leetcode.com/problems/smallest-good-base/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_483.java) & Python |Hard| Others

|486|[Predict the Winner](https://leetcode.com/problems/predict-the-winner/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_486.java) & Python |Medium| Others

|488|[Zuma Game](https://leetcode.com/problems/zuma-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_488.java) & Python |Hard| Others

|491|[Increasing Subsequences](https://leetcode.com/problems/increasing-subsequences/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_491.java) & Python |Medium| Others

|492|[Construct the Rectangle](https://leetcode.com/problems/construct-the-rectangle/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_492.java) & Python |Easy| Others

|493|[Reverse Pairs](https://leetcode.com/problems/reverse-pairs/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_493.java) & Python |Hard| Others

|495|[Teemo Attacking](https://leetcode.com/problems/teemo-attacking/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_495.java) & Python |Medium| Others

|496|[Next Greater Element I](https://leetcode.com/problems/next-greater-element-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_496.java) & Python |Easy| Others

|497|[Random Point in Non-overlapping Rectangles](https://leetcode.com/problems/random-point-in-non-overlapping-rectangles/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_497.java) & Python |Medium| Others

|500|[Keyboard Row](https://leetcode.com/problems/keyboard-row/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_500.java) & Python |Easy| Others

|501|[Find Mode in Binary Search Tree](https://leetcode.com/problems/find-mode-in-binary-search-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_501.java) & Python |Easy| Others

|502|[IPO](https://leetcode.com/problems/ipo/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_502.java) & Python |Hard| Others

|503|[Next Greater Element II](https://leetcode.com/problems/next-greater-element-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_503.java) & Python |Medium| Others

|504|[Base 7](https://leetcode.com/problems/base-7/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_504.java) & Python |Easy| Others

|506|[Relative Ranks](https://leetcode.com/problems/relative-ranks/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_506.java) & Python |Easy| Others

|507|[Perfect Number](https://leetcode.com/problems/perfect-number/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_507.java) & Python |Easy| Others

|508|[Most Frequent Subtree Sum](https://leetcode.com/problems/most-frequent-subtree-sum/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_508.java) & Python |Medium| Others

|513|[Find Bottom Left Tree Value](https://leetcode.com/problems/find-bottom-left-tree-value/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_513.java) & Python |Medium| Others

|514|[Freedom Trail](https://leetcode.com/problems/freedom-trail/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_514.java) & Python |Hard| Others

|515|[Find Largest Value in Each Tree Row](https://leetcode.com/problems/find-largest-value-in-each-tree-row/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_515.java) & Python |Medium| Others

|516|[Longest Palindromic Subsequence](https://leetcode.com/problems/longest-palindromic-subsequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_516.java) & Python |Medium| Others

|517|[Super Washing Machines](https://leetcode.com/problems/super-washing-machines/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_517.java) & Python |Hard| Others

|518|[Coin Change 2](https://leetcode.com/problems/coin-change-2/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_518.java) & Python |Medium| Others

|519|[Random Flip Matrix](https://leetcode.com/problems/random-flip-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_519.java) & Python |Medium| Others

|520|[Detect Capital](https://leetcode.com/problems/detect-capital/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_520.java) & Python |Easy| Others

|521|[Longest Uncommon Subsequence I](https://leetcode.com/problems/longest-uncommon-subsequence-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_521.java) & Python |Easy| Others

|522|[Longest Uncommon Subsequence II](https://leetcode.com/problems/longest-uncommon-subsequence-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_522.java) & Python |Medium| Others

|523|[Continuous Subarray Sum](https://leetcode.com/problems/continuous-subarray-sum/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_523.java) & Python |Medium| Others

|524|[Longest Word in Dictionary through Deleting](https://leetcode.com/problems/longest-word-in-dictionary-through-deleting/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_524.java) & Python |Medium| Others

|525|[Contiguous Array](https://leetcode.com/problems/contiguous-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_525.java) & Python |Medium| Others

|526|[Beautiful Arrangement](https://leetcode.com/problems/beautiful-arrangement/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_526.java) & Python |Medium| Others

|528|[Random Pick with Weight](https://leetcode.com/problems/random-pick-with-weight/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_528.java) & Python |Medium| Others

|529|[Minesweeper](https://leetcode.com/problems/minesweeper/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_529.java) & Python |Medium| Others

|530|[Minimum Absolute Difference in BST](https://leetcode.com/problems/minimum-absolute-difference-in-bst/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_530.java) & Python |Easy| Others

|532|[K-diff Pairs in an Array](https://leetcode.com/problems/k-diff-pairs-in-an-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_532.java) & Python |Easy| Others

|535|[Encode and Decode TinyURL](https://leetcode.com/problems/encode-and-decode-tinyurl/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_535.java) & Python |Medium| Others

|537|[Complex Number Multiplication](https://leetcode.com/problems/complex-number-multiplication/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_537.java) & Python |Medium| Others

|538|[Convert BST to Greater Tree](https://leetcode.com/problems/convert-bst-to-greater-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_538.java) & Python |Easy| Others

|539|[Minimum Time Difference](https://leetcode.com/problems/minimum-time-difference/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_539.java) & Python |Medium| Others

|540|[Single Element in a Sorted Array](https://leetcode.com/problems/single-element-in-a-sorted-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_540.java) & Python |Medium| Others

|541|[Reverse String II](https://leetcode.com/problems/reverse-string-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_541.java) & Python |Easy| Others

|543|[Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_543.java) & Python |Easy| Others

|546|[Remove Boxes](https://leetcode.com/problems/remove-boxes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_546.java) & Python |Hard| Others

|551|[Student Attendance Record I](https://leetcode.com/problems/student-attendance-record-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_551.java) & Python |Easy| Others

|552|[Student Attendance Record II](https://leetcode.com/problems/student-attendance-record-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_552.java) & Python |Hard| Others

|553|[Optimal Division](https://leetcode.com/problems/optimal-division/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_553.java) & Python |Medium| Others

|554|[Brick Wall](https://leetcode.com/problems/brick-wall/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_554.java) & Python |Medium| Others

|556|[Next Greater Element III](https://leetcode.com/problems/next-greater-element-iii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_556.java) & Python |Medium| Others

|558|[Quad Tree Intersection](https://leetcode.com/problems/quad-tree-intersection/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_558.java) & Python |Easy| Others

|560|[Subarray Sum Equals K](https://leetcode.com/problems/subarray-sum-equals-k/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_560.java) & Python |Medium| Others

|563|[Binary Tree Tilt](https://leetcode.com/problems/binary-tree-tilt/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_563.java) & Python |Easy| Others

|564|[Find the Closest Palindrome](https://leetcode.com/problems/find-the-closest-palindrome/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_564.java) & Python |Hard| Others

|565|[Array Nesting](https://leetcode.com/problems/array-nesting/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_565.java) & Python |Medium| Others

|566|[Reshape the Matrix](https://leetcode.com/problems/reshape-the-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_566.java) & Python |Easy| Others

|567|[Permutation in String](https://leetcode.com/problems/permutation-in-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_567.java) & Python |Medium| Others

|572|[Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_572.java) & Python |Easy| Others

|575|[Distribute Candies](https://leetcode.com/problems/distribute-candies/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_575.java) & Python |Easy| Others

|576|[Out of Boundary Paths](https://leetcode.com/problems/out-of-boundary-paths/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_576.java) & Python |Medium| Others

|581|[Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_581.java) & Python |Easy| Others

|583|[Delete Operation for Two Strings](https://leetcode.com/problems/delete-operation-for-two-strings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_583.java) & Python |Medium| Others

|587|[Erect the Fence](https://leetcode.com/problems/erect-the-fence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_587.java) & Python |Hard| Others

|591|[Tag Validator](https://leetcode.com/problems/tag-validator/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_591.java) & Python |Hard| Others

|592|[Fraction Addition and Subtraction](https://leetcode.com/problems/fraction-addition-and-subtraction/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_592.java) & Python |Medium| Others

|593|[Valid Square](https://leetcode.com/problems/valid-square/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_593.java) & Python |Medium| Others

|594|[Longest Harmonious Subsequence](https://leetcode.com/problems/longest-harmonious-subsequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_594.java) & Python |Easy| Others

|598|[Range Addition II](https://leetcode.com/problems/range-addition-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_598.java) & Python |Easy| Others

|600|[Non-negative Integers without Consecutive Ones](https://leetcode.com/problems/non-negative-integers-without-consecutive-ones/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_600.java) & Python |Hard| Others

|605|[Can Place Flowers](https://leetcode.com/problems/can-place-flowers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_605.java) & Python |Easy| Others

|606|[Construct String from Binary Tree](https://leetcode.com/problems/construct-string-from-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_606.java) & Python |Easy| Others

|609|[Find Duplicate File in System](https://leetcode.com/problems/find-duplicate-file-in-system/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_609.java) & Python |Medium| Others

|611|[Valid Triangle Number](https://leetcode.com/problems/valid-triangle-number/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_611.java) & Python |Medium| Others

|617|[Merge Two Binary Trees](https://leetcode.com/problems/merge-two-binary-trees/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_617.java) & Python |Easy| Others

|623|[Add One Row to Tree](https://leetcode.com/problems/add-one-row-to-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_623.java) & Python |Medium| Others

|628|[Maximum Product of Three Numbers](https://leetcode.com/problems/maximum-product-of-three-numbers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_628.java) & Python |Easy| Others

|629|[K Inverse Pairs Array](https://leetcode.com/problems/k-inverse-pairs-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_629.java) & Python |Hard| Others

|630|[Course Schedule III](https://leetcode.com/problems/course-schedule-iii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_630.java) & Python |Hard| Others

|632|[Smallest Range Covering Elements from K Lists](https://leetcode.com/problems/smallest-range-covering-elements-from-k-lists/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_632.java) & Python |Hard| Others

|633|[Sum of Square Numbers](https://leetcode.com/problems/sum-of-square-numbers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_633.java) & Python |Easy| Others

|636|[Exclusive Time of Functions](https://leetcode.com/problems/exclusive-time-of-functions/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_636.java) & Python |Medium| Others

|637|[Average of Levels in Binary Tree](https://leetcode.com/problems/average-of-levels-in-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_637.java) & Python |Easy| Others

|638|[Shopping Offers](https://leetcode.com/problems/shopping-offers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_638.java) & Python |Medium| Others

|639|[Decode Ways II](https://leetcode.com/problems/decode-ways-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_639.java) & Python |Hard| Others

|640|[Solve the Equation](https://leetcode.com/problems/solve-the-equation/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_640.java) & Python |Medium| Others

|641|[Design Circular Deque](https://leetcode.com/problems/design-circular-deque/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_641.java) & Python |Medium| Others

|643|[Maximum Average Subarray I](https://leetcode.com/problems/maximum-average-subarray-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_643.java) & Python |Easy| Others

|645|[Set Mismatch](https://leetcode.com/problems/set-mismatch/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_645.java) & Python |Easy| Others

|646|[Maximum Length of Pair Chain](https://leetcode.com/problems/maximum-length-of-pair-chain/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_646.java) & Python |Medium| Others

|647|[Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_647.java) & Python |Medium| Others

|649|[Dota2 Senate](https://leetcode.com/problems/dota2-senate/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_649.java) & Python |Medium| Others

|650|[2 Keys Keyboard](https://leetcode.com/problems/2-keys-keyboard/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_650.java) & Python |Medium| Others

|653|[Two Sum IV - Input is a BST](https://leetcode.com/problems/two-sum-iv-input-is-a-bst/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_653.java) & Python |Easy| Others

|654|[Maximum Binary Tree](https://leetcode.com/problems/maximum-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_654.java) & Python |Medium| Others

|655|[Print Binary Tree](https://leetcode.com/problems/print-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_655.java) & Python |Medium| Others

|657|[Robot Return to Origin](https://leetcode.com/problems/robot-return-to-origin/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_657.java) & Python |Easy| Others

|659|[Split Array into Consecutive Subsequences](https://leetcode.com/problems/split-array-into-consecutive-subsequences/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_659.java) & Python |Medium| Others

|661|[Image Smoother](https://leetcode.com/problems/image-smoother/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_661.java) & Python |Easy| Others

|662|[Maximum Width of Binary Tree](https://leetcode.com/problems/maximum-width-of-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_662.java) & Python |Medium| Others

|664|[Strange Printer](https://leetcode.com/problems/strange-printer/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_664.java) & Python |Hard| Others

|665|[Non-decreasing Array](https://leetcode.com/problems/non-decreasing-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_665.java) & Python |Easy| Others

|667|[Beautiful Arrangement II](https://leetcode.com/problems/beautiful-arrangement-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_667.java) & Python |Medium| Others

|668|[Kth Smallest Number in Multiplication Table](https://leetcode.com/problems/kth-smallest-number-in-multiplication-table/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_668.java) & Python |Hard| Others

|669|[Trim a Binary Search Tree](https://leetcode.com/problems/trim-a-binary-search-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_669.java) & Python |Easy| Others

|670|[Maximum Swap](https://leetcode.com/problems/maximum-swap/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_670.java) & Python |Medium| Others

|671|[Second Minimum Node In a Binary Tree](https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_671.java) & Python |Easy| Others

|672|[Bulb Switcher II](https://leetcode.com/problems/bulb-switcher-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_672.java) & Python |Medium| Others

|673|[Number of Longest Increasing Subsequence](https://leetcode.com/problems/number-of-longest-increasing-subsequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_673.java) & Python |Medium| Others

|674|[Longest Continuous Increasing Subsequence](https://leetcode.com/problems/longest-continuous-increasing-subsequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_674.java) & Python |Easy| Others

|675|[Cut Off Trees for Golf Event](https://leetcode.com/problems/cut-off-trees-for-golf-event/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_675.java) & Python |Hard| Others

|676|[Implement Magic Dictionary](https://leetcode.com/problems/implement-magic-dictionary/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_676.java) & Python |Medium| Others

|678|[Valid Parenthesis String](https://leetcode.com/problems/valid-parenthesis-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_678.java) & Python |Medium| Others

|679|[24 Game](https://leetcode.com/problems/24-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_679.java) & Python |Hard| Others

|680|[Valid Palindrome II](https://leetcode.com/problems/valid-palindrome-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_680.java) & Python |Easy| Others

|682|[Baseball Game](https://leetcode.com/problems/baseball-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_682.java) & Python |Easy| Others

|684|[Redundant Connection](https://leetcode.com/problems/redundant-connection/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_684.java) & Python |Medium| Others

|685|[Redundant Connection II](https://leetcode.com/problems/redundant-connection-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_685.java) & Python |Hard| Others

|686|[Repeated String Match](https://leetcode.com/problems/repeated-string-match/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_686.java) & Python |Easy| Others

|687|[Longest Univalue Path](https://leetcode.com/problems/longest-univalue-path/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_687.java) & Python |Easy| Others

|688|[Knight Probability in Chessboard](https://leetcode.com/problems/knight-probability-in-chessboard/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_688.java) & Python |Medium| Others

|689|[Maximum Sum of 3 Non-Overlapping Subarrays](https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_689.java) & Python |Hard| Others

|690|[Employee Importance](https://leetcode.com/problems/employee-importance/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_690.java) & Python |Easy| Others

|691|[Stickers to Spell Word](https://leetcode.com/problems/stickers-to-spell-word/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_691.java) & Python |Hard| Others

|692|[Top K Frequent Words](https://leetcode.com/problems/top-k-frequent-words/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_692.java) & Python |Medium| Others

|693|[Binary Number with Alternating Bits](https://leetcode.com/problems/binary-number-with-alternating-bits/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_693.java) & Python |Easy| Others

|695|[Max Area of Island](https://leetcode.com/problems/max-area-of-island/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_695.java) & Python |Medium| Others

|696|[Count Binary Substrings](https://leetcode.com/problems/count-binary-substrings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_696.java) & Python |Easy| Others

|697|[Degree of an Array](https://leetcode.com/problems/degree-of-an-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_697.java) & Python |Easy| Others

|698|[Partition to K Equal Sum Subsets](https://leetcode.com/problems/partition-to-k-equal-sum-subsets/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_698.java) & Python |Medium| Others

|699|[Falling Squares](https://leetcode.com/problems/falling-squares/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_699.java) & Python |Hard| Others

|709|[To Lower Case](https://leetcode.com/problems/to-lower-case/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_709.java) & Python |Easy| Others

|710|[Random Pick with Blacklist](https://leetcode.com/problems/random-pick-with-blacklist/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_710.java) & Python |Hard| Others

|712|[Minimum ASCII Delete Sum for Two Strings](https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_712.java) & Python |Medium| Others

|713|[Subarray Product Less Than K](https://leetcode.com/problems/subarray-product-less-than-k/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_713.java) & Python |Medium| Others

|714|[Best Time to Buy and Sell Stock with Transaction Fee](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_714.java) & Python |Medium| Others

|715|[Range Module](https://leetcode.com/problems/range-module/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_715.java) & Python |Hard| Others

|717|[1-bit and 2-bit Characters](https://leetcode.com/problems/1-bit-and-2-bit-characters/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_717.java) & Python |Easy| Others

|718|[Maximum Length of Repeated Subarray](https://leetcode.com/problems/maximum-length-of-repeated-subarray/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_718.java) & Python |Medium| Others

|720|[Longest Word in Dictionary](https://leetcode.com/problems/longest-word-in-dictionary/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_720.java) & Python |Easy| Others

|721|[Accounts Merge](https://leetcode.com/problems/accounts-merge/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_721.java) & Python |Medium| Others

|722|[Remove Comments](https://leetcode.com/problems/remove-comments/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_722.java) & Python |Medium| Others

|725|[Split Linked List in Parts](https://leetcode.com/problems/split-linked-list-in-parts/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_725.java) & Python |Medium| Others

|726|[Number of Atoms](https://leetcode.com/problems/number-of-atoms/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_726.java) & Python |Hard| Others

|728|[Self Dividing Numbers](https://leetcode.com/problems/self-dividing-numbers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_728.java) & Python |Easy| Others

|729|[My Calendar I](https://leetcode.com/problems/my-calendar-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_729.java) & Python |Medium| Others

|730|[Count Different Palindromic Subsequences](https://leetcode.com/problems/count-different-palindromic-subsequences/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_730.java) & Python |Hard| Others

|731|[My Calendar II](https://leetcode.com/problems/my-calendar-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_731.java) & Python |Medium| Others

|732|[My Calendar III](https://leetcode.com/problems/my-calendar-iii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_732.java) & Python |Hard| Others

|735|[Asteroid Collision](https://leetcode.com/problems/asteroid-collision/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_735.java) & Python |Medium| Others

|736|[Parse Lisp Expression](https://leetcode.com/problems/parse-lisp-expression/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_736.java) & Python |Hard| Others

|738|[Monotone Increasing Digits](https://leetcode.com/problems/monotone-increasing-digits/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_738.java) & Python |Medium| Others

|740|[Delete and Earn](https://leetcode.com/problems/delete-and-earn/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_740.java) & Python |Medium| Others

|741|[Cherry Pickup](https://leetcode.com/problems/cherry-pickup/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_741.java) & Python |Hard| Others

|743|[Network Delay Time](https://leetcode.com/problems/network-delay-time/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_743.java) & Python |Medium| Others

|745|[Prefix and Suffix Search](https://leetcode.com/problems/prefix-and-suffix-search/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_745.java) & Python |Hard| Others

|746|[Min Cost Climbing Stairs](https://leetcode.com/problems/min-cost-climbing-stairs/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_746.java) & Python |Easy| Others

|748|[Shortest Completing Word](https://leetcode.com/problems/shortest-completing-word/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_748.java) & Python |Easy| Others

|749|[Contain Virus](https://leetcode.com/problems/contain-virus/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_749.java) & Python |Hard| Others

|753|[Cracking the Safe](https://leetcode.com/problems/cracking-the-safe/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_753.java) & Python |Hard| Others

|754|[Reach a Number](https://leetcode.com/problems/reach-a-number/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_754.java) & Python |Easy| Others

|756|[Pyramid Transition Matrix](https://leetcode.com/problems/pyramid-transition-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_756.java) & Python |Medium| Others

|757|[Set Intersection Size At Least Two](https://leetcode.com/problems/set-intersection-size-at-least-two/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_757.java) & Python |Hard| Others

|761|[Special Binary String](https://leetcode.com/problems/special-binary-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_761.java) & Python |Hard| Others

|762|[Prime Number of Set Bits in Binary Representation](https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representation/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_762.java) & Python |Easy| Others

|763|[Partition Labels](https://leetcode.com/problems/partition-labels/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_763.java) & Python |Medium| Others

|764|[Largest Plus Sign](https://leetcode.com/problems/largest-plus-sign/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_764.java) & Python |Medium| Others

|765|[Couples Holding Hands](https://leetcode.com/problems/couples-holding-hands/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_765.java) & Python |Hard| Others

|766|[Toeplitz Matrix](https://leetcode.com/problems/toeplitz-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_766.java) & Python |Easy| Others

|767|[Reorganize String](https://leetcode.com/problems/reorganize-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_767.java) & Python |Medium| Others

|768|[Max Chunks To Make Sorted II](https://leetcode.com/problems/max-chunks-to-make-sorted-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_768.java) & Python |Hard| Others

|769|[Max Chunks To Make Sorted](https://leetcode.com/problems/max-chunks-to-make-sorted/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_769.java) & Python |Medium| Others

|770|[Basic Calculator IV](https://leetcode.com/problems/basic-calculator-iv/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_770.java) & Python |Hard| Others

|773|[Sliding Puzzle](https://leetcode.com/problems/sliding-puzzle/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_773.java) & Python |Hard| Others

|775|[Global and Local Inversions](https://leetcode.com/problems/global-and-local-inversions/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_775.java) & Python |Medium| Others

|777|[Swap Adjacent in LR String](https://leetcode.com/problems/swap-adjacent-in-lr-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_777.java) & Python |Medium| Others

|778|[Swim in Rising Water](https://leetcode.com/problems/swim-in-rising-water/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_778.java) & Python |Hard| Others

|780|[Reaching Points](https://leetcode.com/problems/reaching-points/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_780.java) & Python |Hard| Others

|781|[Rabbits in Forest](https://leetcode.com/problems/rabbits-in-forest/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_781.java) & Python |Medium| Others

|782|[Transform to Chessboard](https://leetcode.com/problems/transform-to-chessboard/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_782.java) & Python |Hard| Others

|783|[Minimum Distance Between BST Nodes](https://leetcode.com/problems/minimum-distance-between-bst-nodes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_783.java) & Python |Easy| Others

|784|[Letter Case Permutation](https://leetcode.com/problems/letter-case-permutation/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_784.java) & Python |Easy| Others

|785|[Is Graph Bipartite?](https://leetcode.com/problems/is-graph-bipartite/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_785.java) & Python |Medium| Others

|786|[K-th Smallest Prime Fraction](https://leetcode.com/problems/k-th-smallest-prime-fraction/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_786.java) & Python |Hard| Others

|787|[Cheapest Flights Within K Stops](https://leetcode.com/problems/cheapest-flights-within-k-stops/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_787.java) & Python |Medium| Others

|788|[Rotated Digits](https://leetcode.com/problems/rotated-digits/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_788.java) & Python |Easy| Others

|789|[Escape The Ghosts](https://leetcode.com/problems/escape-the-ghosts/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_789.java) & Python |Medium| Others

|790|[Domino and Tromino Tiling](https://leetcode.com/problems/domino-and-tromino-tiling/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_790.java) & Python |Medium| Others

|791|[Custom Sort String](https://leetcode.com/problems/custom-sort-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_791.java) & Python |Medium| Others

|792|[Number of Matching Subsequences](https://leetcode.com/problems/number-of-matching-subsequences/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_792.java) & Python |Medium| Others

|793|[Preimage Size of Factorial Zeroes Function](https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_793.java) & Python |Hard| Others

|794|[Valid Tic-Tac-Toe State](https://leetcode.com/problems/valid-tic-tac-toe-state/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_794.java) & Python |Medium| Others

|795|[Number of Subarrays with Bounded Maximum](https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_795.java) & Python |Medium| Others

|796|[Rotate String](https://leetcode.com/problems/rotate-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_796.java) & Python |Easy| Others

|797|[All Paths From Source to Target](https://leetcode.com/problems/all-paths-from-source-to-target/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_797.java) & Python |Medium| Others

|798|[Smallest Rotation with Highest Score](https://leetcode.com/problems/smallest-rotation-with-highest-score/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_798.java) & Python |Hard| Others

|799|[Champagne Tower](https://leetcode.com/problems/champagne-tower/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_799.java) & Python |Medium| Others

|801|[Minimum Swaps To Make Sequences Increasing](https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_801.java) & Python |Medium| Others

|802|[Find Eventual Safe States](https://leetcode.com/problems/find-eventual-safe-states/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_802.java) & Python |Medium| Others

|803|[Bricks Falling When Hit](https://leetcode.com/problems/bricks-falling-when-hit/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_803.java) & Python |Hard| Others

|804|[Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_804.java) & Python |Easy| Others

|805|[Split Array With Same Average](https://leetcode.com/problems/split-array-with-same-average/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_805.java) & Python |Hard| Others

|806|[Number of Lines To Write String](https://leetcode.com/problems/number-of-lines-to-write-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_806.java) & Python |Easy| Others

|807|[Max Increase to Keep City Skyline](https://leetcode.com/problems/max-increase-to-keep-city-skyline/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_807.java) & Python |Medium| Others

|808|[Soup Servings](https://leetcode.com/problems/soup-servings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_808.java) & Python |Medium| Others

|809|[Expressive Words](https://leetcode.com/problems/expressive-words/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_809.java) & Python |Medium| Others

|810|[Chalkboard XOR Game](https://leetcode.com/problems/chalkboard-xor-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_810.java) & Python |Hard| Others

|811|[Subdomain Visit Count](https://leetcode.com/problems/subdomain-visit-count/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_811.java) & Python |Easy| Others

|812|[Largest Triangle Area](https://leetcode.com/problems/largest-triangle-area/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_.java) & Python |Easy| Others

|813|[Largest Sum of Averages](https://leetcode.com/problems/largest-sum-of-averages/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_813.java) & Python |Medium| Others

|814|[Binary Tree Pruning](https://leetcode.com/problems/binary-tree-pruning/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_814.java) & Python |Medium| Others

|815|[Bus Routes](https://leetcode.com/problems/bus-routes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_815.java) & Python |Hard| Others

|816|[Ambiguous Coordinates](https://leetcode.com/problems/ambiguous-coordinates/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_816.java) & Python |Medium| Others

|817|[Linked List Components](https://leetcode.com/problems/linked-list-components/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_817.java) & Python |Medium| Others

|818|[Race Car ](https://leetcode.com/problems/most-common-word/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_818.java) & Python |Hard| Others

|819|[Most Common Word](https://leetcode.com/problems/most-common-word/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_819.java) & Python |Easy| Others

|820|[Short Encoding of Words](https://leetcode.com/problems/short-encoding-of-words/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_820.java) & Python |Medium| Others

|821|[Shortest Distance to a Character](https://leetcode.com/problems/shortest-distance-to-a-character/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_821.java) & Python |Easy| Others

|822|[Card Flipping Game](https://leetcode.com/problems/card-flipping-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_822.java) & Python |Medium| Others

|823|[Binary Trees With Factors](https://leetcode.com/problems/binary-trees-with-factors/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_823.java) & Python |Medium| Others

|824|[Goat Latin](https://leetcode.com/problems/goat-latin/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_824.java) & Python |Easy| Others

|825|[Friends Of Appropriate Ages](https://leetcode.com/problems/friends-of-appropriate-ages/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_825.java) & Python |Medium| Others

|826|[Most Profit Assigning Work](https://leetcode.com/problems/most-profit-assigning-work/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_826.java) & Python |Medium| Others

|827|[Making A Large Island](https://leetcode.com/problems/making-a-large-island/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_827.java) & Python |Hard| Others

|828|[Unique Letter String](https://leetcode.com/problems/unique-letter-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_828.java) & Python |Hard| Others

|829|[Consecutive Numbers Sum](https://leetcode.com/problems/consecutive-numbers-sum/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_829.java) & Python |Hard| Others

|830|[Positions of Large Groups](https://leetcode.com/problems/positions-of-large-groups/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_830.java) & Python |Easy| Others

|831|[Masking Personal Information](https://leetcode.com/problems/masking-personal-information/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_831.java) & Python |Medium| Others

|832|[Flipping an Image](https://leetcode.com/problems/flipping-an-image/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_832.java) & Python |Easy| Others

|833|[Find And Replace in String](https://leetcode.com/problems/find-and-replace-in-string/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_833.java) & Python |Medium| Others

|834|[Sum of Distances in Tree](https://leetcode.com/problems/sum-of-distances-in-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_834.java) & Python |Hard| Others

|835|[Image Overlap](https://leetcode.com/problems/image-overlap/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_835.java) & Python |Medium| Others

|836|[Rectangle Overlap](https://leetcode.com/problems/rectangle-overlap/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_836.java) & Python |Easy| Others

|837|[New 21 Game](https://leetcode.com/problems/new-21-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_837.java) & Python |Medium| Others

|838|[Push Dominoes](https://leetcode.com/problems/push-dominoes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_838.java) & Python |Medium| Others

|839|[Similar String Groups](https://leetcode.com/problems/similar-string-groups/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_839.java) & Python |Hard| Others

|840|[Magic Squares In Grid](https://leetcode.com/problems/magic-squares-in-grid/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_840.java) & Python |Easy| Others

|842|[Split Array into Fibonacci Sequence](https://leetcode.com/problems/split-array-into-fibonacci-sequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_842.java) & Python |Medium| Others

|843|[Guess the Word](https://leetcode.com/problems/guess-the-word/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_843.java) & Python |Hard| Others

|844|[Backspace String Compare](https://leetcode.com/problems/backspace-string-compare/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_844.java) & Python |Easy| Others

|845|[Longest Mountain in Array](https://leetcode.com/problems/longest-mountain-in-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_845.java) & Python |Medium| Others

|846|[Hand of Straights](https://leetcode.com/problems/hand-of-straights/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_846.java) & Python |Medium| Others

|847|[Shortest Path Visiting All Nodes](https://leetcode.com/problems/shortest-path-visiting-all-nodes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_847.java) & Python |Hard| Others

|848|[Shifting Letters](https://leetcode.com/problems/shifting-letters/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_848.java) & Python |Medium| Others

|849|[Maximize Distance to Closest Person](https://leetcode.com/problems/maximize-distance-to-closest-person/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_849.java) & Python |Easy| Others

|850|[Rectangle Area II](https://leetcode.com/problems/rectangle-area-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_850.java) & Python |Hard| Others

|851|[Loud and Rich](https://leetcode.com/problems/loud-and-rich/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_851.java) & Python |Medium| Others

|852|[Peak Index in a Mountain Array](https://leetcode.com/problems/peak-index-in-a-mountain-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_852.java) & Python |Easy| Others

|853|[Car Fleet](https://leetcode.com/problems/car-fleet/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_853.java) & Python |Medium| Others

|854|[K-Similar Strings](https://leetcode.com/problems/k-similar-strings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_854.java) & Python |Hard| Others

|855|[Exam Room](https://leetcode.com/problems/exam-room/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_855.java) & Python |Medium| Others

|856|[Score of Parentheses](https://leetcode.com/problems/score-of-parentheses/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_856.java) & Python |Medium| Others

|857|[Minimum Cost to Hire K Workers](https://leetcode.com/problems/minimum-cost-to-hire-k-workers/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_857.java) & Python |Hard| Others

|858|[Mirror Reflection](https://leetcode.com/problems/mirror-reflection/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_858.java) & Python |Medium| Others

|859|[Buddy Strings](https://leetcode.com/problems/buddy-strings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_859.java) & Python |Easy| Others

|860|[Lemonade Change](https://leetcode.com/problems/lemonade-change/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_860.java) & Python |Easy| Others

|861|[Score After Flipping Matrix](https://leetcode.com/problems/score-after-flipping-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_861.java) & Python |Medium| Others

|862|[Shortest Subarray with Sum at Least K](https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_862.java) & Python |Hard| Others

|863|[All Nodes Distance K in Binary Tree](https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_863.java) & Python |Medium| Others

|864|[Shortest Path to Get All Keys](https://leetcode.com/problems/shortest-path-to-get-all-keys/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_864.java) & Python |Hard| Others

|865|[Smallest Subtree with all the Deepest Nodes](https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_865.java) & Python |Medium| Others

|866|[Prime Palindrome](https://leetcode.com/problems/prime-palindrome/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_866.java) & Python |Medium| Others

|867|[Transpose Matrix](https://leetcode.com/problems/transpose-matrix/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_867.java) & Python |Easy| Others

|868|[Binary Gap](https://leetcode.com/problems/binary-gap/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_868.java) & Python |Easy| Others

|869|[Reordered Power of 2](https://leetcode.com/problems/reordered-power-of-2/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_869.java) & Python |Medium| Others

|870|[Advantage Shuffle](https://leetcode.com/problems/advantage-shuffle/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_870.java) & Python |Medium| Others

|871|[Minimum Number of Refueling Stops](https://leetcode.com/problems/minimum-number-of-refueling-stops/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_871.java) & Python |Hard| Others

|872|[Leaf-Similar Trees](https://leetcode.com/problems/leaf-similar-trees/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_872.java) & Python |Easy| Others

|873|[Length of Longest Fibonacci Subsequence](https://leetcode.com/problems/length-of-longest-fibonacci-subsequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_873.java) & Python |Medium| Others

|874|[Walking Robot Simulation](https://leetcode.com/problems/walking-robot-simulation/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_874.java) & Python |Easy| Others

|875|[Koko Eating Bananas](https://leetcode.com/problems/koko-eating-bananas/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_875.java) & Python |Medium| Others

|876|[Middle of the Linked List](https://leetcode.com/problems/middle-of-the-linked-list/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_876.java) & Python |Easy| Others

|877|[Stone Game](https://leetcode.com/problems/stone-game/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_877.java) & Python |Medium| Others

|878|[Nth Magical Number](https://leetcode.com/problems/nth-magical-number/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_878.java) & Python |Hard| Others

|879|[Profitable Schemes](https://leetcode.com/problems/profitable-schemes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_879.java) & Python |Hard| Others

|880|[Decoded String at Index](https://leetcode.com/problems/decoded-string-at-index/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_880.java) & Python |Medium| Others

|881|[Boats to Save People](https://leetcode.com/problems/boats-to-save-people/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_881.java) & Python |Medium| Others

|882|[Reachable Nodes In Subdivided Graph](https://leetcode.com/problems/reachable-nodes-in-subdivided-graph/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_882.java) & Python |Hard| Others

|883|[Projection Area of 3D Shapes](https://leetcode.com/problems/projection-area-of-3d-shapes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_883.java) & Python |Easy| Others

|884|[Uncommon Words from Two Sentences](https://leetcode.com/problems/uncommon-words-from-two-sentences/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_884.java) & Python |Easy| Others

|885|[Spiral Matrix III](https://leetcode.com/problems/spiral-matrix-iii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_885.java) & Python |Medium| Others

|886|[Possible Bipartition](https://leetcode.com/problems/possible-bipartition/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_886.java) & Python |Medium| Others

|887|[Super Egg Drop](https://leetcode.com/problems/super-egg-drop/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_887.java) & Python |Hard| Others

|888|[Fair Candy Swap](https://leetcode.com/problems/fair-candy-swap/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_888.java) & Python |Easy| Others

|889|[Construct Binary Tree from Preorder and Postorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_889.java) & Python |Medium| Others

|890|[Find and Replace Pattern](https://leetcode.com/problems/find-and-replace-pattern/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_890.java) & Python |Medium| Others

|891|[Sum of Subsequence Widths](https://leetcode.com/problems/sum-of-subsequence-widths/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_891.java) & Python |Hard| Others

|892|[Surface Area of 3D Shapes](https://leetcode.com/problems/surface-area-of-3d-shapes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_892.java) & Python |Easy| Others

|893|[Groups of Special-Equivalent Strings](https://leetcode.com/problems/groups-of-special-equivalent-strings/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_893.java) & Python |Easy| Others

|894|[All Possible Full Binary Trees](https://leetcode.com/problems/all-possible-full-binary-trees/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_894.java) & Python |Medium| Others

|895|[Maximum Frequency Stack](https://leetcode.com/problems/maximum-frequency-stack/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_895.java) & Python |Hard| Others

|896|[Monotonic Array](https://leetcode.com/problems/monotonic-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_896.java) & Python |Easy| Others

|897|[Increasing Order Search Tree](https://leetcode.com/problems/increasing-order-search-tree/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_897.java) & Python |Easy| Others

|898|[Bitwise ORs of Subarrays](https://leetcode.com/problems/bitwise-ors-of-subarrays/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_898.java) & Python |Medium| Others

|899|[Orderly Queue](https://leetcode.com/problems/orderly-queue/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_899.java) & Python |Hard| Others

|900|[RLE Iterator](https://leetcode.com/problems/rle-iterator/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_900.java) & Python |Medium| Others

|901|[Online Stock Span](https://leetcode.com/problems/online-stock-span/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_901.java) & Python |Medium| Others

|902|[Numbers At Most N Given Digit Set](https://leetcode.com/problems/numbers-at-most-n-given-digit-set/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_902.java) & Python |Hard| Others

|903|[Valid Permutations for DI Sequence](https://leetcode.com/problems/valid-permutations-for-di-sequence/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_903.java) & Python |Hard| Others

|904|[Fruit Into Baskets](https://leetcode.com/problems/fruit-into-baskets/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_904.java) & Python |Medium| Others

|905|[Sort Array By Parity](https://leetcode.com/problems/sort-array-by-parity/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_905.java) & Python |Easy| Others

|906|[Super Palindromes](https://leetcode.com/problems/super-palindromes/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_906.java) & Python |Hard| Others

|907|[Sum of Subarray Minimums](https://leetcode.com/problems/sum-of-subarray-minimums/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_907.java) & Python |Medium| Others

|908|[Smallest Range I](https://leetcode.com/problems/smallest-range-i/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_908.java) & Python |Easy| Others

|909|[Snakes and Ladders](https://leetcode.com/problems/snakes-and-ladders/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_909.java) & Python |Medium| Others

|910|[Smallest Range II](https://leetcode.com/problems/smallest-range-ii/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_910.java) & Python |Medium| Others

|911|[Online Election](https://leetcode.com/problems/online-election/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_911.java) & Python |Medium| Others

|913|[Cat and Mouse](https://leetcode.com/problems/cat-and-mouse/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_913.java) & Python |Hard| Others

|914|[X of a Kind in a Deck of Cards](https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_914.java) & Python |Easy| Others

|915|[Partition Array into Disjoint Intervals ](https://leetcode.com/problems/partition-array-into-disjoint-intervals/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/others/_915.java) & Python |Medium| Others

### Shell

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|192|[Word Frequency](https://leetcode.com/problems/word-frequency/description/)|[bash](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/shell/_192.sh) |Medium| Shell

|193|[Valid Phone Numbers](https://leetcode.com/problems/valid-phone-numbers/description/)|[bash](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/shell/_193.sh) |Easy| Shell

|194|[Transpose File](https://leetcode.com/problems/transpose-file/description/)|[bash](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/shell/_194.sh) |Medium| Shell

|195|[Tenth Line](https://leetcode.com/problems/tenth-line/description/)|[bash](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/shell/_195.sh) |Easy| Shell

### Database

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|175|[Combine Two Tables](https://leetcode.com/problems/combine-two-tables/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_175.sql) |Easy| Database

|176|[Second Highest Salary](https://leetcode.com/problems/second-highest-salary/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_176.sql) |Easy| Database

|177|[Nth Highest Salary](https://leetcode.com/problems/nth-highest-salary/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_177.sql) |Medium| Database

|178|[Rank Scores](https://leetcode.com/problems/rank-scores/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_178.sql) |Medium| Database

|180|[Consecutive Numbers](https://leetcode.com/problems/consecutive-numbers/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_180.sql) |Medium| Database

|181|[Employees Earning More Than Their Managers](https://leetcode.com/problems/employees-earning-more-than-their-managers/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_181.sql) |Easy| Database

|182|[Duplicate Emails](https://leetcode.com/problems/duplicate-emails/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_182.sql) |Easy| Database

|183|[Customers Who Never Order](https://leetcode.com/problems/customers-who-never-order/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_183.sql) |Easy| Database

|184|[Department Highest Salary](https://leetcode.com/problems/department-highest-salary/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_184.sql) |Medium| Database

|185|[Department Top Three Salaries](https://leetcode.com/problems/department-top-three-salaries/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_185.sql) |Hard| Database

|196|[Delete Duplicate Emails](https://leetcode.com/problems/delete-duplicate-emails/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_196.sql) |Easy| Database

|197|[Rising Temperature](https://leetcode.com/problems/rising-temperature/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_197.sql) |Easy| Database

|262|[Trips and Users](https://leetcode.com/problems/trips-and-users/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_262.sql) |Hard| Database

|595|[Big Countries](https://leetcode.com/problems/big-countries/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_595.sql) |Easy| Database

|596|[Classes More Than 5 Students](https://leetcode.com/problems/classes-more-than-5-students/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_596.sql) |Easy| Database

|601|[Human Traffic of Stadium](https://leetcode.com/problems/human-traffic-of-stadium/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_601.sql) |Hard| Database

|620|[Not Boring Movies](https://leetcode.com/problems/not-boring-movies/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_620.sql) |Easy| Database

|626|[Exchange Seats](https://leetcode.com/problems/exchange-seats/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_626.sql) |Medium| Database

|627|[Swap Salary](https://leetcode.com/problems/swap-salary/description/)|[MySQL](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/database/_627.sql) |Easy| Database

### Sort Algorithm

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|Sort 1|[Bubble Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/BubbleSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/BubbleSort.py)|Easy| Sort Algorithm

|Sort 2|[Insert Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/InsertSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/InsertSort.py)|Easy| Sort Algorithm

|Sort 3|[Select Sort](https://github.com/guobinhit/myleetcode#sort-algorithm) | [Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/SelectSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/SelectSort.py)|Easy| Sort Algorithm

|Sort 4|[Quick Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/QuickSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/QuickSort.py)|Easy| Sort Algorithm

|Sort 5|[Merge Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/MergeSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/MergeSort.py)|Medium| Sort Algorithm

|Sort 6|[Heap Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/HeapSort.java)  & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/sort_algorithm/HeapSort.py)|Medium| Sort Algorithm

|Sort 7|[Bucket Sort](https://github.com/guobinhit/myleetcode#sort-algorithm)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/sort_algorithm/BucketSort.java)  & Python|Easy| Sort Algorithm

### Search Algorithm

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|Search 1|[Binary Search](https://github.com/guobinhit/myleetcode#search-algorithm) | [Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/search_algorithm/BinarySearch.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/search_algorithm/BinarySearch.py)|Easy| Search Algorithm

|Search 2|[Interpolation Search](https://github.com/guobinhit/myleetcode#search-algorithm) | [Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/search_algorithm/InterpolationSearch.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/search_algorithm/InterpolationSearch.py)|Easy| Search Algorithmx

|Search 3|[Order Search](https://github.com/guobinhit/myleetcode#search-algorithm) | [Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basinfo/search_algorithm/OrderSearch.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basinfo/search_algorithm/OrderSearch.py)|Easy| Search Algorithm

## Interview

### Top Interview Questions

#### Easy Collection

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|1|[Two Sum](https://leetcode.com/problems/two-sum/description/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_1.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/1.go) |Easy| Array

|7|[Reverse Integer](https://leetcode.com/problems/reverse-integer/description/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/strings/_7.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/7.go) |Easy| Strings

|8|[String to Integer (atoi)](https://leetcode.com/problems/string-to-integer-atoi/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/strings/_8.java) & Python |Medium| Strings

|13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/math/_13.java) & Python |Easy| Math

|14|[Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_14.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/14.go)|Easy| Strings

|19|[Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_19.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/19.go)|Medium| Linked List

|20|[Valid Parentheses](https://leetcode.com/problems/valid-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_20.java) & Python|Easy| Others

|21|[Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_21.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/21.go)|Easy| Linked List

|26|[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_26.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/26.go)|Easy| Array

|28|[Implement strStr()](https://leetcode.com/problems/implement-strstr/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_28.java) & Python|Easy| Strings

|36|[Valid Sudoku](https://leetcode.com/problems/valid-sudoku/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_36.java) & Python |Medium| Array

|38|[Count and Say](https://leetcode.com/problems/count-and-say/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/strings/_38.java) & Python |Easy| Strings

|48|[Rotate Image](https://leetcode.com/problems/rotate-image/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/array/_48.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/48.go)  |Medium| Array

|53|[Maximum Subarray](https://leetcode.com/problems/maximum-subarray/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/dynamic_programming/_53.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/interview/top_interview_questions/easy_collection/dynamic_programming/_53.py) |Easy| Dynamic Programming

|66|[Plus One](https://leetcode.com/problems/plus-one/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_66.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/66.go)|Easy| Array

|70|[Climbing Stairs](https://leetcode.com/problems/climbing-stairs/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_70.java) & Python| Easy| Dynamic Programming

|88|[Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/sorting_and_searching/_88.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/88.go) |Easy| Sorting and Searching

|98|[Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_98.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/98.go) |Medium| Trees

|101|[Symmetric Tree](https://leetcode.com/problems/symmetric-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_101.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/101.go) |Easy| Trees

|102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_102.java) & Python |Medium| Trees

|104|[Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_104.java) & Python |Easy| Trees

|108|[Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_108.java) & Python |Easy| Trees

|118|[Pascal's Triangle](https://leetcode.com/problems/pascals-triangle/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_118.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/7.go)| Easy| Others

|121|[Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/dynamic_programming/_121.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/121.go) |Easy| Dynamic Programming

|122|[Best Time to Buy and Sell Stock II](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/array/_122.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/122.go)|Easy| Array

|125|[Valid Palindrome](https://leetcode.com/problems/valid-palindrome/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/strings/_125.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/125.go) |Easy| Strings

|136|[Single Number](https://leetcode.com/problems/single-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_136.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/136.go) |Easy| Array

|141|[Linked List Cycle](https://leetcode.com/problems/linked-list-cycle/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_141.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/141.go)|Easy| Linked List

|155|[Min Stack](https://leetcode.com/problems/min-stack/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_155.java) & Python|Easy| Design

|189|[Rotate Array](https://leetcode.com/problems/rotate-array/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_189.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/189.go)| Easy| Array

|190|[Reverse Bits](https://leetcode.com/problems/reverse-bits/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/others/_190.java) & Python |Easy| Others

|191|[Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/description/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/others/_191.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/191.go) |Easy| Others

|198|[House Robber](https://leetcode.com/problems/house-robber/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/dynamic_programming/_198.java) & Python |Easy| Dynamic Programming

|204|[Count Primes](https://leetcode.com/problems/count-primes/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/math/_204.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/204.go) |Easy| Math

|206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_206.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/206.go)|Easy| Linked List

|217|[Contains Duplicate](https://leetcode.com/problems/contains-duplicate/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_217.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/217.go) |Easy| Array

|234|[Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_234.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/234.go)|Easy| Linked List

|237|[Delete Node in a Linked List](https://leetcode.com/problems/delete-node-in-a-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/linked_list/_237.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/237.go) |Easy| Linked List

|242|[Valid Anagram](https://leetcode.com/problems/valid-anagram/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/strings/_242.java) & Python |Easy| Strings

|268|[Missing Number](https://leetcode.com/problems/missing-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/others/_268.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/268.go) |Easy| Others

|278|[First Bad Version](https://leetcode.com/problems/first-bad-version/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_278.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_278.py)|Easy| Sorting and Searching

|283|[Move Zeroes](https://leetcode.com/problems/move-zeroes/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_283.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/283.go)| Easy| Array

|326|[Power of Three](https://leetcode.com/problems/power-of-three/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/math/_326.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/326.go) |Easy| Math

|344|[Reverse String](https://leetcode.com/problems/reverse-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_344.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/344.go) | Easy| Strings

|350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_350.java) & Python |Easy| Array

|384|[Shuffle an Array](https://leetcode.com/problems/shuffle-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/design/_384.java) & Python |Medium| Design

|387|[First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_387.java) & Python |Easy| Strings

|412|[Fizz Buzz](https://leetcode.com/problems/fizz-buzz/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/math/_412.java) & Python |Easy| Math

|461|[Hamming Distance](https://leetcode.com/problems/hamming-distance/description/)|[Java](../master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/easy_collection/others/_461.java) & [Go](../master/codes/go/leetcodes/interview/easy_collection/461.go) |Easy| Others

#### Medium Collection

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_2.java) & Python|Medium| Linked List

|3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_3.java) & Python |Medium| Array and Strings

|5|[Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_5.java) & Python |Medium| Array and Strings

|15|[3Sum](https://leetcode.com/problems/3sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_15.java) & Python |Medium| Array and Strings

|17|[Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/recursion_ii/_17.java) & Python |Medium| Backtracking

|22|[Generate Parentheses](https://leetcode.com/problems/generate-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_22.java) & Python |Medium| Backtracking

|29|[Divide Two Integers](https://leetcode.com/problems/divide-two-integers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/math/_29.java) & Python |Medium| Math

|33|[Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_33.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_33.py)|Medium| Sorting and Searching

|34|[Find First and Last Position of Element in Sorted Array](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_34.java) & Python |Medium| Sorting and Searching

|46|[Permutations](https://leetcode.com/problems/permutations/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_46.java) & Python |Medium| Backtracking

|49|[Group Anagrams](https://leetcode.com/problems/group-anagrams/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_49.java) & Python |Medium| Array and Strings

|50|[Pow(x, n)](https://leetcode.com/problems/powx-n/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_50.java) & Python |Medium| Math

|55|[Jump Game](https://leetcode.com/problems/jump-game/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/dynamic_programming/_55.java) & Python |Medium| Dynamic Programming

|56|[Merge Intervals](https://leetcode.com/problems/merge-intervals/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/sorting_and_searching/_56.java) & Python |Medium| Sorting and Searching

|62|[Unique Paths](https://leetcode.com/problems/unique-paths/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/dynamic_programming/_62.java) & Python |Medium| Dynamic Programming

|69|[Sqrt(x)](https://leetcode.com/problems/sqrtx/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_69.java) & [Python](https://github.com/guobinhit/myleetcode/blob/master/codes/python/leetcodes/src/main/python/com/hit/basmath/learn/binary_search/_69.py)|Easy| Math

|73|[Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_73.java) & Python |Medium| Array and Strings

|75|[Sort Colors](https://leetcode.com/problems/sort-colors/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/sorting_and_searching/_75.java) & Python |Medium| Sorting and Searching

|78|[Subsets](https://leetcode.com/problems/subsets/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_78.java) & Python |Medium| Backtracking

|79|[Word Search](https://leetcode.com/problems/word-search/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_79.java) & Python |Medium| Backtracking

|94|[Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_94.java) & Python |Medium| Trees and Graphs

|103|[Binary Tree Zigzag Level Order Traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/trees_and_graphs/_103.java) & Python |Medium| Trees and Graphs

|105|[Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_105.java) & Python |Medium| Trees and Graphs

|116|[Populating Next Right Pointers in Each Node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_116.java) & Python |Medium| Trees and Graphs

|150|[Evaluate Reverse Polish Notation](https://leetcode.com/problems/evaluate-reverse-polish-notation/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_150.java) & Python|Medium| Others

|160|[Intersection of Two Linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_160.java) & Python|Easy| Linked List

|162|[Find Peak Element](https://leetcode.com/problems/find-peak-element/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_162.java) & Python|Medium| Sorting and Searching

|166|[Fraction to Recurring Decimal](https://leetcode.com/problems/fraction-to-recurring-decimal/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/math/_166.java) & Python |Medium| Math

|169|[Majority Element](https://leetcode.com/problems/majority-element/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/others/_169.java) & Python |Easy| Others

|171|[Excel Sheet Column Number](https://leetcode.com/problems/excel-sheet-column-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/math/_171.java) & Python |Easy| Math

|172|[Factorial Trailing Zeroes](https://leetcode.com/problems/factorial-trailing-zeroes/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/math/_172.java) & Python |Easy| Math

|200|[Number of Islands](https://leetcode.com/problems/number-of-islands/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_200.java) & Python|Medium| Trees and Graphs

|202|[Happy Number](https://leetcode.com/problems/happy-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_202.java) & Python |Easy| Math

|215|[Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/sorting_and_searching/_215.java) & Python |Medium| Sorting and Searching

|230|[Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/trees_and_graphs/_230.java) & Python |Medium| Trees and Graphs

|240|[Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_240.java) & Python |Medium| Sorting and Searching

|297|[Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_297.java) & Python |Medium| Design

|300|[Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/dynamic_programming/_300.java) & Python |Medium| Dynamic Programming

|322|[Coin Change](https://leetcode.com/problems/coin-change/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/dynamic_programming/_322.java) & Python |Medium| Dynamic Programming

|328|[Odd Even Linked List](https://leetcode.com/problems/odd-even-linked-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_328.java) & Python|Medium| Linked List

|334|[Increasing Triplet Subsequence](https://leetcode.com/problems/increasing-triplet-subsequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/array_and_strings/_334.java) & Python |Medium| Array and Strings

|347|[Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_347.java) & Python |Medium| Sorting and Searching

|371|[Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/others/_371.java) & Python |Easy| Others

|380|[Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_380.java) & Python |Medium| Design

|621|[Task Scheduler](https://leetcode.com/problems/task-scheduler/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/medium_collection/others/_621.java) & Python |Medium| Others

#### Hard Collection

|  #  |      Title     |   Solutions    |   Difficulty  | Tag                   

|-----|----------------|:---------------:|:--------:|:-------------:

|4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_4.java) & Python |Hard| Sorting and Searching

|10|[Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/backtracking/_10.java) & Python |Hard| Backtracking

|11|[Container With Most Water](https://leetcode.com/problems/container-with-most-water/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_11.java) & Python |Medium| Array and Strings

|23|[Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/linked_list/_23.java) & Python |Hard| Linked List

|41|[First Missing Positive](https://leetcode.com/problems/first-missing-positive/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_41.java) & Python |Hard| Array and Strings

|42|[Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/others/_42.java) & Python |Hard| Others

|44|[Wildcard Matching](https://leetcode.com/problems/wildcard-matching/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/backtracking/_44.java) & Python |Hard| Backtracking

|54|[Spiral Matrix](https://leetcode.com/problems/spiral-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/array_and_string/_54.java) & Python|Medium| Array and Strings

|76|[Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_76.java) & Python |Hard| Array and Strings

|84|[Largest Rectangle in Histogram](https://leetcode.com/problems/largest-rectangle-in-histogram/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_84.java) & Python |Hard| Others

|91|[Decode Ways](https://leetcode.com/problems/decode-ways/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_91.java) & Python |Medium| Dynamic Programming

|124|[Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_124.java) & Python |Hard| Trees and Graphs

|127|[Word Ladder](https://leetcode.com/problems/word-ladder/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_127.java) & Python |Medium| Trees and Graphs

|128|[Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_128.java) & Python |Hard| Array and Strings

|130|[Surrounded Regions](https://leetcode.com/problems/surrounded-regions/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_130.java) & Python |Medium| Trees and Graphs

|131|[Palindrome Partitioning](https://leetcode.com/problems/palindrome-partitioning/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/backtracking/_131.java) & Python |Medium| Backtracking

|135|[Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/linked_list/_135.java) & Python|Medium| Linked List

|139|[Word Break](https://leetcode.com/problems/word-break/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_139.java) & Python |Medium| Dynamic Programming

|140|[Word Break II](https://leetcode.com/problems/word-break-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_140.java) & Python |Hard| Dynamic Programming

|146|[LRU Cache](https://leetcode.com/problems/lru-cache/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/design/_146.java) & Python |Medium| Design

|148|[Sort List](https://leetcode.com/problems/sort-list/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/linked_list/_148.java) & Python |Medium| Linked List

|149|[Max Points on a Line](https://leetcode.com/problems/max-points-on-a-line/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/math/_149.java) & Python |Hard| Math

|152|[Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_152.java) & Python |Medium| Dynamic Programming

|179|[Largest Number](https://leetcode.com/problems/largest-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/math/_179.java) & Python |Medium| Math

|207|[Course Schedule](https://leetcode.com/problems/course-schedule/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_207.java) & Python |Medium| Trees and Graphs

|208|[Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_208.java) & Python |Medium| Design

|210|[Course Schedule II](https://leetcode.com/problems/course-schedule-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_210.java) & Python |Medium| Trees and Graphs

|212|[Word Search II](https://leetcode.com/problems/word-search-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/trie/_212.java) & Python |Hard| Backtracing

|218|[The Skyline Problem](https://leetcode.com/problems/the-skyline-problem/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search_tree/_218.java) & Python |Hard| Others

|227|[Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_227.java) & Python |Medium| Array and Strings

|236|[Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_tree/_236.java) & Python |Medium| Trees and Graphs

|238|[Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_238.java) & Python |Medium| Array and Strings

|239|[Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_239.java) & Python |Hard| Array and Strings

|279|[Perfect Squares](https://leetcode.com/problems/perfect-squares/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/queue_stack/_279.java) & Python|Medium| Dynamic Programming

|287|[Find the Duplicate Number](https://leetcode.com/problems/find-the-duplicate-number/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/binary_search/_287.java) & Python |Medium| Array and Strings

|289|[Game of Life](https://leetcode.com/problems/game-of-life/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/array_and_strings/_289.java) & Python |Medium| Array and Strings

|295|[Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/design/_295.java) & Python |Hard| Design

|301|[Remove Invalid Parentheses](https://leetcode.com/problems/remove-invalid-parentheses/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/backtracking/_301.java) & Python |Hard| Backtracking

|309|[Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_309.java) & Python |Medium| Dynamic Programming

|312|[Burst Balloons](https://leetcode.com/problems/burst-balloons/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/dynamic_programming/_312.java) & Python |Hard| Dynamic Programming

|315|[Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_315.java) & Python |Hard| Trees and Graphs

|324|[Wiggle Sort II](https://leetcode.com/problems/wiggle-sort-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/sorting_and_searching/_324.java) & Python |Medium| Sorting and Searching

|329|[Longest Increasing Path in a Matrix](https://leetcode.com/problems/longest-increasing-path-in-a-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_329.java) & Python |Hard| Trees and Graphs

|341|[Flatten Nested List Iterator](https://leetcode.com/problems/flatten-nested-list-iterator/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/design/_341.java) & Python |Medium| Design

|378|[Kth Smallest Element in a Sorted Matrix](https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/sorting_and_searching/_378.java) & Python |Medium| Sorting and Searching

|406|[Queue Reconstruction by Height](https://leetcode.com/problems/queue-reconstruction-by-height/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/others/_406.java) & Python |Medium| Others

|454|[4Sum II](https://leetcode.com/problems/4sum-ii/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/learn/hash_table/_454.java) & Python |Medium| Array and Strings

|547|[Friend Circles](https://leetcode.com/problems/friend-circles/description/)|[Java](https://github.com/guobinhit/myleetcode/blob/master/codes/java/leetcodes/src/main/java/com/hit/basmath/interview/top_interview_questions/hard_collection/trees_and_graphs/_547.java) & Python |Medium| Trees and Graphs

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