https://github.com/rajeevranjancom/leetcode_python
Leetcode Python Solution. Those who Want to learn Python From Scratch check out the Website linked below. Good Luck.
https://github.com/rajeevranjancom/leetcode_python
competative-programming competitive-programming-contests leetcode-python leetcode-solutions pycharm pycharm-ide python2 python3 pytorch
Last synced: 4 months ago
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Leetcode Python Solution. Those who Want to learn Python From Scratch check out the Website linked below. Good Luck.
- Host: GitHub
- URL: https://github.com/rajeevranjancom/leetcode_python
- Owner: rajeevranjancom
- License: gpl-3.0
- Created: 2020-09-20T12:02:38.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-11-04T20:41:12.000Z (over 5 years ago)
- Last Synced: 2025-04-06T02:32:00.265Z (about 1 year ago)
- Topics: competative-programming, competitive-programming-contests, leetcode-python, leetcode-solutions, pycharm, pycharm-ide, python2, python3, pytorch
- Language: Python
- Homepage: https://www.python.org/doc/
- Size: 1010 KB
- Stars: 3
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# leetcode_Python
# copyRight@Rajeev Ranjan
## Links:
| Websites |
|-----------------|
| https://www.python.org/doc/ (Documentation Releases by Version) |
| https://www.python.org/downloads/ (Download the latest source release)|
| https://docs.python.org/3/tutorial/ (The Python Tutorial) |
| https://www.python.org/about/gettingstarted/ (Python For Beginners)|
| https://docs.python.org/3/library/ (The Python Standard Library)|
| https://wiki.python.org/moin/PythonPeriodicals (PythonPeriodicals)|
| https://packaging.python.org/ (Python Packaging User Guide)|
| https://pyvideo.org/ (Python related videos)|
| https://docs.python.org/3/ (Python 3.8.6rc1 documentation)|
## Notes:
| Important |
|------------------|
| Python is an interpreted, high-level and general-purpose programming language. Created by Guido van Rossum and first released in 1991, Python's design philosophy emphasizes code readability with its notable use of significant whitespace. |
| Typing discipline: Duck, dynamic, gradual (since 3.5) |
| Designed by: Guido van Rossum |
| OS: Linux, macOS, Windows Vista (and newer) and more |
| Filename extensions: .py,.pyi,.pyc,.pyd,.pyo (prior to 3.5),.pyw,.pyz (since 3.5) |
## Table
| # | Title | Solution | Difficulty | Tag |
|-----|---------------- | --------------- | --------------- | -----|
| 1 | [Two Sum](https://leetcode.com/problems/two-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/001.%20Two%20Sum.cpp) | Easy | Array / Hash Table |
| 2 | [Add Two Numbers](https://leetcode.com/problems/add-two-numbers/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/002.%20Add%20Two%20Numbers.cpp) | Medium | Linked List |
| 3 | [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/003.%20Longest%20Substring%20Without%20Repeating%20Characters.cpp) | Medium | Hash Table / Two Pointers |
| 4 | [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/004.%20Median%20of%20Two%20Sorted%20Arrays.cpp) | Hard | Array / Binary Search |
| 5 | [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/005.%20Longest%20Palindromic%20Substring.cpp) | Medium | String |
| 6 | [ZigZag Conversion](https://leetcode.com/problems/zigzag-conversion/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/006.%20ZigZag%20Conversion.cpp) | Medium | String |
| 7 | [Reverse Integer](https://leetcode.com/problems/reverse-integer/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/007.%20Reverse%20Integer.cpp) | Easy | Math |
| 8 | [String to Integer (atoi)](https://leetcode.com/problems/string-to-integer-atoi/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/008.%20String%20to%20Integer%20(atoi).cpp) | Medium | String |
| 9 | [Palindrome Number](https://leetcode.com/problems/palindrome-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/009.%20Palindrome%20Number.cpp) | Easy | Math |
| 10 | [Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/010.%20Regular%20Expression%20Matching.cpp) | Hard | String / Dynamic Programming / Backtracking |
| 11 | [Container With Most Water](https://leetcode.com/problems/container-with-most-water/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/011.%20Container%20With%20Most%20Water.cpp) | Medium | Array / Two Pointers |
| 12 | [Integer to Roman](https://leetcode.com/problems/integer-to-roman/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/012.%20Integer%20to%20Roman.cpp) | Medium | String |
| 13 | [Roman to Integer](https://leetcode.com/problems/roman-to-integer/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/013.%20Roman%20to%20Integer.cpp) | Easy | String |
| 14 | [Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/014.%20Longest%20Common%20Prefix.cpp) | Easy | String |
| 15 | [3Sum](https://leetcode.com/problems/3sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/015.%203Sum.cpp) | Medium | Array / Two Pointers |
| 16 | [3Sum Closest](https://leetcode.com/problems/3sum-closest/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/016.%203Sum%20Closest.cpp) | Medium | Array / Two Pointers |
| 17 | [Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/017.%20Letter%20Combinations%20of%20a%20Phone%20Number.cpp) | Medium | Backtracking / String |
| 18 | [4Sum](https://leetcode.com/problems/4sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/018.%204Sum.cpp) | Medium | Array |
| 19 | [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/019.%20Remove%20Nth%20Node%20From%20End%20of%20List.cpp) | Medium | Linked List / Two Pointers |
| 20 | [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/020.%20Valid%20Parentheses.cpp) | Easy | Stack |
| 21 | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/021.%20Merge%20Two%20Sorted%20Lists.cpp) | Easy | Linked List |
| 22 | [Generate Parentheses](https://leetcode.com/problems/generate-parentheses/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/022.%20Generate%20Parentheses.cpp) | Medium | String / Backtracking |
| 23 | [Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/023.%20Merge%20k%20Sorted%20Lists.cpp) | Hard | Linked List / Heap |
| 24 | [Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/024.%20Swap%20Nodes%20in%20Pairs.cpp) | Medium | Linked List |
| 25 | [Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/025.%20Reverse%20Nodes%20in%20k-Group.cpp) | Hard | Linked List |
| 26 | [Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/026.%20Remove%20Duplicates%20from%20Sorted%20Array.cpp) | Easy | Array / Two Pointers |
| 27 | [Remove Element](https://leetcode.com/problems/remove-element/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/027.%20Remove%20Element.cpp) | Easy | Array / Two Pointers |
| 28 | [Implement strStr()](https://leetcode.com/problems/implement-strstr/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/028.%20Implement%20strStr().cpp) | Easy | String |
| 29 | [Implement strStr()](https://leetcode.com/problems/implement-strstr/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/029.cpp) | Easy | String |
| 31 | [Next Permutation](https://leetcode.com/problems/next-permutation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/031.%20Next%20Permutation.cpp) | Medium | Array |
| 33 | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/033.%20Search%20in%20Rotated%20Sorted%20Array.cpp) | Medium | Array / Binary Search |
| 34 | [Search for a Range](https://leetcode.com/problems/search-for-a-range/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/034.%20Search%20for%20a%20Range.cpp) | Medium | Array / Binary Search |
| 35 | [Search Insert Position](https://leetcode.com/problems/search-insert-position/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/035.%20Search%20Insert%20Position.cpp) | Easy | Array / Binary Search |
| 36 | [Valid Sudoku](https://leetcode.com/problems/valid-sudoku/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/036.%20Valid%20Sudoku.cpp) | Medium | Hash Table |
| 37 | [Sudoku Solver](https://leetcode.com/problems/valid-sudoku/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/037.%20Sudoku%20Solver.cpp) | Medium | Hash Table |
| 38 | [Count and Say](https://leetcode.com/problems/count-and-say/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/038.%20Count%20and%20Say.cpp) | Easy | String |
| 39 | [Combination Sum](https://leetcode.com/problems/combination-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/039.%20Combination%20Sum.cpp) | Medium | Array / Backtracking |
| 40 | [Combination Sum II](https://leetcode.com/problems/combination-sum-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/040.%20Combination%20Sum%20II.cpp) | Medium | Array / Backtracking |
| 41 | [First Missing Positive](https://leetcode.com/problems/first-missing-positive/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/041.%20First%20Missing%20Positive.cpp) | Hard | Array |
| 42 | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/042.%20Trapping%20Rain%20Water.cpp) | Hard | Array / Two Pointers / Stack |
| 43 | [Multiply Strings](https://leetcode.com/problems/multiply-strings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/043.%20Multiply%20Strings.cpp) | Medium | String |
| 44 | [Wildcard Matching](https://leetcode.com/problems/wildcard-matching/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/044.%20Wildcard%20Matching.cpp) | Hard | String / Backtracking / Greedy |
| 45 | [Jump Game II](https://leetcode.com/problems/jump-game-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/045.%20Jump%20Game%20II.cpp) | Hard | Array / Greedy |
| 46 | [Permutations](https://leetcode.com/problems/permutations/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/046.%20Permutations.cpp) | Medium | Backtracking |
| 47 | [Permutations II](https://leetcode.com/problems/permutations-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/047.%20Permutations%20II.cpp) | Medium | Backtracking |
| 48 | [Rotate Image](https://leetcode.com/problems/rotate-image/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/048.%20Rotate%20Image.cpp) | Medium | Matrix |
| 49 | [Group Anagrams](https://leetcode.com/problems/group-anagrams/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/049.%20Group%20Anagrams.cpp) | Medium | Hash Table / String |
| 50 | [Pow(x, n)](https://leetcode.com/problems/powx-n/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/050.%20Pow(x%2C%20n).cpp) | Medium | Binary Search |
| 51 | [Pow(x, n)](https://leetcode.com/problems/powx-n/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/051.%20N-Queens.cpp) | Medium | Binary Search |
| 52 | [Pow(x, n)](https://leetcode.com/problems/powx-n/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/052.%20N-Queens%20II.cpp) | Medium | Binary Search |
| 53 | [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/053.%20Maximum%20Subarray.cpp) | Easy | Dynamic Programming / Array |
| 54 | [Spiral Matrix](https://leetcode.com/problems/spiral-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/054.%20Spiral%20Matrix.cpp) | Medium | Array |
| 55 | [Jump Game](https://leetcode.com/problems/jump-game/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/055.%20Jump%20Game.cpp) | Medium | Array / Greedy |
| 56 | [Merge Intervals](https://leetcode.com/problems/merge-intervals/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/056.%20Merge%20Intervals.cpp) | Medium | Array / Sort |
| 57 | [Insert Interval](https://leetcode.com/problems/insert-interval/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/057.%20Insert%20Interval.cpp) | Hard | Array / Sort |
| 58 | [Length of Last Word](https://leetcode.com/problems/length-of-last-word/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/058.%20Length%20of%20Last%20Word.cpp) | Easy | String |
| 59 | [Spiral Matrix II](https://leetcode.com/problems/spiral-matrix-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/059.%20Spiral%20Matrix%20II.cpp) | Medium | Array |
| 60 | [Permutation Sequence](https://leetcode.com/problems/permutation-sequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/060.%20Permutation%20Sequence.cpp) | Medium | Backtracking / Math |
| 61 | [Rotate List](https://leetcode.com/problems/rotate-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/061.%20Rotate%20List.cpp) | Medium | Linked List / Two Pointers |
| 62 | [Unique Paths](https://leetcode.com/problems/unique-paths/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/062.%20Unique%20Paths.cpp) | Medium | Array / Dynamic Programming |
| 63 | [Unique Paths II](https://leetcode.com/problems/unique-paths-ii/description/) | [C++](https://github.com/fengvyi/LeetCode/blob/master/C%2B%2B/063.%20Unique%20Paths%20II.cpp) | Medium | Array / Dynamic Programming |
| 64 | [Minimum Path Sum](https://leetcode.com/problems/minimum-path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/064.%20Minimum%20Path%20Sum.cpp) | Medium | Array / Dynamic Programming |
| 65 | [Valid Number](https://leetcode.com/problems/minimum-path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/065.%20Valid%20Number.cpp) | Medium | Array / Dynamic Programming |
| 66 | [Plus One](https://leetcode.com/problems/plus-one/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/066.%20Plus%20One.cpp) | Easy | Array / Math |
| 67 | [Add Binary](https://leetcode.com/problems/add-binary/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/067.%20Add%20Binary.cpp) | Easy | String |
| 68 | [Text Justification](https://leetcode.com/problems/text-justification/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/068.%20Text%20Justification.cpp) | Hard | String |
| 69 | [Sqrt(x)](https://leetcode.com/problems/sqrtx/description/) | [C++](https://github.com/fengvyi/LeetCode/blob/master/C%2B%2B/069.%20Sqrt(x).cpp) | Easy | Binary Search / Math |
| 70 | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/070.%20Climbing%20Stairs.cpp) | Easy | Dynamic Programming |
| 71 | [Simplify Path](https://leetcode.com/problems/simplify-path/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/071.%20Simplify%20Path.cpp) | Medium | Stack / String |
| 72 | [Edit Distance](https://leetcode.com/problems/simplify-path/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/072.%20Edit%20Distance.cpp) | Medium | Stack / String |
| 73 | [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/073.%20Set%20Matrix%20Zeroes.cpp) | Medium | Array |
| 74 | [Search a 2D Matrix](https://leetcode.com/problems/search-a-2d-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/074.%20Search%20a%202D%20Matrix.cpp) | Medium | Array / Binary Search |
| 75 | [Sort Colors](https://leetcode.com/problems/sort-colors/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/075.%20Sort%20Colors.cpp) | Medium | Array / Two Pointers |
| 76 | [Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/076.%20Minimum%20Window%20Substring.cpp) | Hard | Hash Table / Two pointers / String |
| 78 | [Subsets](https://leetcode.com/problems/subsets/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/078.%20Subsets.cpp) | Medium | Array / Backtracking |
| 79 | [Word Search](https://leetcode.com/problems/word-search/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/079.%20Word%20Search.cpp) | Medium | Matrix / Backtracking |
| 80 | [Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/080.%20Remove%20Duplicates%20from%20Sorted%20Array%20II.cpp) | Medium | Array / Two Pointers |
| 82 | [Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/082.%20Remove%20Duplicates%20from%20Sorted%20List%20II.cpp) | Medium | Linked List |
| 83 | [Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/083.%20Remove%20Duplicates%20from%20Sorted%20List.cpp) | Easy | Linked List |
| 84 | [Largest Rectangle in Histogram](https://leetcode.com/problems/maximal-rectangle/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/084.%20Largest%20Rectangle%20in%20Histogram.cpp) | Hard | Array |
| 85 | [Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle/description/) | [C++](https://github.com/fengvyi/LeetCode/blob/master/C%2B%2B/085.%20Maximal%20Rectangle.cpp) | Hard | Array |
| 86 | [Partition List](https://leetcode.com/problems/partition-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/086.%20Partition%20List.cpp) | Medium | Linked List |
| 88 | [Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/088.%20Merge%20Sorted%20Array.cpp) | Easy | Array / Two Pointers |
| 90 | [Subsets II](https://leetcode.com/problems/subsets-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/090.%20Subsets%20II.cpp) | Medium | Array / Backtracking |
| 91 | [Decode Ways](https://leetcode.com/problems/decode-ways/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/091.%20Decode%20Ways.cpp) | Medium | Dynamic Programming / String |
| 92 | [Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/092.%20Reverse%20Linked%20List%20II.cpp) | Medium | Linked List |
| 94 | [Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/094.%20Binary%20Tree%20Inorder%20Traversal.cpp) | Medium | Tree / Stack |
| 95 | [Unique Binary Search Trees II](https://leetcode.com/problems/unique-binary-search-trees-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/095.%20Unique%20Binary%20Search%20Trees%20II.cpp) | Medium | Tree |
| 96 | [Unique Binary Search Trees](https://leetcode.com/problems/recover-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/096.%20Unique%20Binary%20Search%20Trees.cpp) | Hard | Tree / DFS |
| 97 | [Interleaving String](https://leetcode.com/problems/recover-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/097.%20Interleaving%20String.cpp) | Hard | Tree / DFS |
| 98 | [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/098.%20Validate%20Binary%20Search%20Tree.cpp) | Medium | Tree |
| 99 | [Recover Binary Search Tree](https://leetcode.com/problems/recover-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/099.%20Recover%20Binary%20Search%20Tree.cpp) | Hard | Tree / DFS |
| 100 | [Same Tree](https://leetcode.com/problems/same-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/100.%20Same%20Tree.cpp) | Easy | Tree / DFS |
| 101 | [Symmetric Tree](https://leetcode.com/problems/symmetric-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/101.%20Symmetric%20Tree.cpp) | Easy | Tree |
| 102 | [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/102.%20Binary%20Tree%20Level%20Order%20Traversal.cpp) | Medium | Tree / DFS / BFS |
| 103 | [Binary Tree Zigzag Level Order Traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/103.%20Binary%20Tree%20Zigzag%20Level%20Order%20Traversal.cpp) | Medium | Tree / BFS |
| 104 | [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/104.%20Maximum%20Depth%20of%20Binary%20Tree.cpp) | Easy | Tree |
| 105 | [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/105.%20Construct%20Binary%20Tree%20from%20Preorder%20and%20Inorder%20Traversal.cpp) | Medium | Array / Tree / DFS |
| 106 | [Construct Binary Tree from Inorder and Postorder Traversal](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/106.%20Construct%20Binary%20Tree%20from%20Inorder%20and%20Postorder%20Traversal.cpp) | Medium | Linked List / DFS |
| 107 | [Binary Tree Level Order Traversal II](https://leetcode.com/problems/binary-tree-level-order-traversal-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/107.%20Binary%20Tree%20Level%20Order%20Traversal%20II.cpp) | Easy | Tree |
| 108 | [Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/108.%20Convert%20Sorted%20Array%20to%20Binary%20Search%20Tree.cpp) | Easy | Tree / DFS |
| 109 | [Convert Sorted List to Binary Search Tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/109.%20Convert%20Sorted%20List%20to%20Binary%20Search%20Tree.cpp) | Medium | Linked List / DFS |
| 110 | [Balanced Binary Tree](https://leetcode.com/problems/balanced-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/110.%20Balanced%20Binary%20Tree.cpp) | Easy | Tree / DFS |
| 111 | [Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/111.%20Minimum%20Depth%20of%20Binary%20Tree.cpp) | Easy | Tree |
| 112 | [Path Sum](https://leetcode.com/problems/path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/112.%20Path%20Sum.cpp) | Easy | Tree / DFS |
| 113 | [Path Sum II](https://leetcode.com/problems/path-sum-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/113.%20Path%20Sum%20II.cpp) | Medium | Tree / DFS |
| 114 | [Flatten Binary Tree to Linked List](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/114.%20Flatten%20Binary%20Tree%20to%20Linked%20List.cpp) | Medium | Tree / DFS |
| 116 | [Populating Next Right Pointers in Each Node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/116.%20Populating%20Next%20Right%20Pointers%20in%20Each%20Node.cpp) | Medium | Tree / BFS |
| 117 | [Populating Next Right Pointers in Each Node II](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/117.%20Populating%20Next%20Right%20Pointers%20in%20Each%20Node%20II.cpp) | Medium | Tree / Level-order Traversal |
| 118 | [Pascal's Triangle](https://leetcode.com/problems/pascals-triangle/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/118.%20Pascal's%20Triangle.cpp) | Easy | Array | [discuss](https://leetcode.com/problems/pascals-triangle/discuss/123054/9-lines-C++-recursion) |
| 119 | [Pascal's Triangle II](https://leetcode.com/problems/pascals-triangle-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/119.%20Pascal's%20Triangle%20II.cpp) | Easy | Array |
| 120 | [Triangle](https://leetcode.com/problems/triangle/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/120.%20Triangle.cpp) | Medium | Array / Dynamic Programming |
| 121 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/121.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock.cpp) | Easy | Array / Dynamic Programming |
| 122 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/binary-tree-maximum-path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/122.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock%20II.cpp) | Hard | Tree / DFS |
| 123 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/binary-tree-maximum-path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/123.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock%20III.cpp) | Hard | Tree / DFS | [discuss](https://discuss.leetcode.com/topic/104532/8-lines-c-similar-to-diameter-of-tree) |
| 124 | [Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/124.%20Binary%20Tree%20Maximum%20Path%20Sum.cpp) | Hard | Tree / DFS |
| 125 | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/125.%20Valid%20Palindrome.cpp) | Easy | String / Two Pointers |
| 126 | [Word Ladder ](https://leetcode.com/problems/longest-consecutive-sequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/126.%20Word%20Ladder%20II.cpp) | Hard | Array / Unoin Find |
| 127 | [Word Ladder](https://leetcode.com/problems/word-ladder/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/127.%20Word%20Ladder.cpp) | Medium | String / BFS | [discuss](https://discuss.leetcode.com/topic/101076/clean-c-bfs) |
| 128 | [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/128.%20Longest%20Consecutive%20Sequence.cpp) | Hard | Array / Unoin Find | [discuss](https://discuss.leetcode.com/topic/100724/10-lines-c) |
| 129 | [Sum Root to Leaf Numbers](https://leetcode.com/problems/sum-root-to-leaf-numbers/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/129.%20Sum%20Root%20to%20Leaf%20Numbers.cpp) | Medium | Tree / DFS / BFS | [discuss](https://leetcode.com/problems/sum-root-to-leaf-numbers/discuss/121401/C++-DFS-and-BFS-solution) |
| 130 | [Surrounded Regions](https://leetcode.com/problems/surrounded-regions/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/130.%20Surrounded%20Regions.cpp) | Medium | DFS / BFS / Union Find | [discuss](https://discuss.leetcode.com/topic/119417/c-dfs-union-find-solution) |
| 131 | [Palindrome Partitioning](https://leetcode.com/problems/palindrome-partitioning/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/131.%20Palindrome%20Partitioning.cpp) | Medium | Backtracking | [discuss](https://leetcode.com/problems/palindrome-partitioning/discuss/129637/C++-backtracking) |
| 132 | [Palindrome Partitioning](https://leetcode.com/problems/single-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/132.%20Palindrome%20Partitioning%20II.cpp) | Easy | Bit Manipulation | [discuss](https://leetcode.com/problems/single-number/discuss/129372/3-lines-C++) |
| 133 | [Clone Graph](https://leetcode.com/problems/clone-graph/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/133.%20Clone%20Graph.cpp) | Medium | Graph / DFS / BFS | [discuss](https://discuss.leetcode.com/topic/101082/clean-c-dfs-29ms) |
| 134 | [Gas Station](https://leetcode.com/problems/gas-station/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/134.%20Gas%20Station.cpp) | Medium | Greedy | [discuss](https://leetcode.com/problems/gas-station/discuss/198746/Simple-C++-greedy) |
| 136 | [Single Number](https://leetcode.com/problems/single-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/136.%20Single%20Number.cpp) | Easy | Bit Manipulation | [discuss](https://leetcode.com/problems/single-number/discuss/129372/3-lines-C++) |
| 137 | [Single Numberll](https://leetcode.com/problems/word-break/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/137.%20Single%20Number%20II.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/101231/clean-c-9ms-dp) |
| 138 | [Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/138.%20Copy%20List%20with%20Random%20Pointer.cpp) | Medium | Hash Table / Linked List | [discuss](https://leetcode.com/problems/copy-list-with-random-pointer/discuss/131629/Simple-C++-hashmap-solution) |
| 139 | [Word Break](https://leetcode.com/problems/word-break/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/139.%20Word%20Break.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/101231/clean-c-9ms-dp) |
| 140 | [Word BreakII](https://leetcode.com/problems/word-break/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/140.%20Word%20Break%20II.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/101231/clean-c-9ms-dp) |
| 141 | [Linked List Cycle](https://leetcode.com/problems/linked-list-cycle/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/141.%20Linked%20List%20Cycle.cpp) | Easy | Linked List / Two Pointers | [discuss](https://leetcode.com/problems/linked-list-cycle/discuss/131632/7-lines-C++) |
| 142 | [Linked List Cycle II](https://leetcode.com/problems/linked-list-cycle-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/142.%20Linked%20List%20Cycle%20II.cpp) | Medium | Linked List / Two Pointers | [discuss](https://leetcode.com/problems/linked-list-cycle-ii/discuss/131635/10ms-C++-solution) |
| 143 | [Reorder List](https://leetcode.com/problems/reorder-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/143.%20Reorder%20List.cpp) | Medium | Linked List | [discuss](https://discuss.leetcode.com/topic/96122/clear-c-o-1-space-solution) |
| 144 | [Binary Tree Preorder Traversal](https://leetcode.com/problems/binary-tree-preorder-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/144.%20Binary%20Tree%20Preorder%20Traversal.cpp) | Medium | Tree / Stack |
| 145 | [Binary Tree Postorder Traversal](https://leetcode.com/problems/binary-tree-postorder-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/145.%20Binary%20Tree%20Postorder%20Traversal.cpp) | Hard | Tree / Stack | [discuss](https://discuss.leetcode.com/topic/107713/c-iterative-recursive-solutions) |
| 146 | [LRU Cache](https://leetcode.com/problems/lru-cache/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/146.%20LRU%20Cache.cpp) | Hard | Design | [discuss](https://discuss.leetcode.com/topic/109805/concise-c-82ms-hash-table-deque-solution) |
| 147 | [Insertion Sort List](https://leetcode.com/problems/min-stack/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/147.%20Insertion%20Sort%20List.cpp) | Easy | Stack / Design | [discuss](https://discuss.leetcode.com/topic/105788/8-lines-c) |
| 148 | [Sort List](https://leetcode.com/problems/min-stack/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/148.%20Sort%20List.cpp) | Easy | Stack / Design | [discuss](https://discuss.leetcode.com/topic/105788/8-lines-c) |
| 149 | [ Max Points on a Line](https://leetcode.com/problems/min-stack/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/149.%20Max%20Points%20on%20a%20Line.cpp) | Easy | Stack / Design | [discuss](https://discuss.leetcode.com/topic/105788/8-lines-c) |
| 151 | [Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/151.%20Reverse%20Words%20in%20a%20String.cpp) | Medium | String | [discuss](https://discuss.leetcode.com/topic/102920/c-o-1-space) |
| 152 | [Maximum Product Subarray](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/152.%20Maximum%20Product%20Subarray.cpp) | Hard | String / Two Pointers | [discuss](https://discuss.leetcode.com/topic/108306/c-two-pointers-unordered_set) |
| 153 | [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/153.%20Find%20Minimum%20in%20Rotated%20Sorted%20Array.cpp) | Hard | String / Two Pointers | [discuss](https://discuss.leetcode.com/topic/108306/c-two-pointers-unordered_set) |
| 154 | [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/154.%20Find%20Minimum%20in%20Rotated%20Sorted%20Array%20II.cpp) | Hard | String / Two Pointers |
| 155 | [Min Stack](https://leetcode.com/problems/min-stack/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/155.%20Min%20Stack.cpp) | Easy | Stack / Design |
| 157 | [Read N Characters Given Read4](https://leetcode.com/problems/read-n-characters-given-read4/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/157.%20Read%20N%20Characters%20Given%20Read4.cpp) | Easy | String |
| 158 | [Read N Characters Given Read4 II - Call multiple times](https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/158.%20Read%20N%20Characters%20Given%20Read4%20II%20-%20Call%20multiple%20times.cpp) | Hard | String |
| 159 | [Longest Substring with At Most Two Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/159.%20Longest%20Substring%20with%20At%20Most%20Two%20Distinct%20Characters.cpp) | Hard | String / Two Pointers |
| 160 | [Intersection of Two Linked Lists](https://leetcode.com/problems/one-edit-distance/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/160.%20Intersection%20of%20Two%20Linked%20Lists.cpp) | Medium | String |
| 161 | [One Edit Distance](https://leetcode.com/problems/one-edit-distance/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/161.%20One%20Edit%20Distance.cpp) | Medium | String |
| 162 | [Find Peak Element](https://leetcode.com/problems/find-peak-element/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/162.%20Find%20Peak%20Element.cpp) | Medium | Binary Search |
| 163 | [Missing Ranges](https://leetcode.com/problems/missing-ranges/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/163.%20Missing%20Ranges.cpp) | Medium | Array |
| 168 | [Excel Sheet Column Title](https://leetcode.com/problems/excel-sheet-column-title/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/168.%20Excel%20Sheet%20Column%20Title.cpp) | Easy | Math |
| 169 | [Majority Element](https://leetcode.com/problems/majority-element/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/169.%20Majority%20Element.cpp) | Easy | Array |
| 171 | [Excel Sheet Column Number](https://leetcode.com/problems/excel-sheet-column-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/171.%20Excel%20Sheet%20Column%20Number.cpp) | Easy | Math | [discuss](https://leetcode.com/problems/excel-sheet-column-number/discuss/134153/6-lines-C++) |
| 173 | [Binary Search Tree Iterator](https://leetcode.com/problems/binary-search-tree-iterator/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/173.%20Binary%20Search%20Tree%20Iterator.cpp) | Medium | Tree / Stack / Design |
| 186 | [Reverse Words in a String II](https://leetcode.com/problems/reverse-words-in-a-string-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/186.%20Reverse%20Words%20in%20a%20String%20II.cpp) | Medium | String |
| 191 | [Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/191.%20Number%20of%201%20Bits.cpp) | Easy | Bit Manipulation |
| 198 | [House Robber](https://leetcode.com/problems/house-robber/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/198.%20House%20Robber.cpp) | Easy | Dynamic Programming |
| 200 | [Number of Islands](https://leetcode.com/problems/number-of-islands/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/200.%20Number%20of%20Islands.cpp) | Medium | BFS / Union Find |
| 205 | [Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/205.%20Isomorphic%20Strings.cpp) | Easy | Hash Table |
| 206 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/206.%20Reverse%20Linked%20List.cpp) | Easy | Linked List |
| 207 | [Course Schedule](https://leetcode.com/problems/course-schedule/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/207.%20Course%20Schedule.cpp) | Medium | Graph / BFS / Topological Sort |
| 208 | [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/208.%20Implement%20Trie%20(Prefix%20Tree).cpp) | Medium | Trie / Design |
| 209 | [Minimum Size Subarray Sum](https://leetcode.com/problems/minimum-size-subarray-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/209.%20Minimum%20Size%20Subarray%20Sum.cpp) | Medium | Array / Two Pointers |
| 210 | [Course Schedule II](https://leetcode.com/problems/course-schedule-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/210.%20Course%20Schedule%20II.cpp) | Medium | Graph / BFS / Topological Sort |
| 211 | [Add and Search Word - Data structure design](https://leetcode.com/problems/add-and-search-word-data-structure-design/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/211.%20Add%20and%20Search%20Word%20-%20Data%20structure%20design.cpp) | Medium | Design / Trie | [discuss](https://discuss.leetcode.com/topic/100013/c-62ms-beats-100) |
| 212 | [Word Search II](https://leetcode.com/problems/word-search-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/212.%20Word%20Search%20II.cpp) | Hard | Backtracking / Trie | [discuss](https://discuss.leetcode.com/topic/83017/c-462-ms-brute-force-and-35-ms-trie-solution) |
| 214 | [Shortest Palindrome](https://leetcode.com/problems/shortest-palindrome/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/214.%20Shortest%20Palindrome.cpp) | Hard | String |
| 215 | [Kth Largest Element in an Array](https://leetcode.com/problems/kth-largest-element-in-an-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/215.%20Kth%20Largest%20Element%20in%20an%20Array.cpp) | Medium | Sort / Partition |
| 221 | [Maximal Square](https://leetcode.com/problems/maximal-square/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/221.%20Maximal%20Square.cpp) | Medium | Dynamic Programming / BFS |
| 223 | [Rectangle Area](https://leetcode.com/problems/rectangle-area/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/223.%20Rectangle%20Area.cpp) | Medium | Math |
| 224 | [Basic Calculator](https://leetcode.com/problems/basic-calculator/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/224.%20Basic%20Calculator.cpp) | Hard | String / Stack | [discuss](https://discuss.leetcode.com/topic/108357/c-13ms-stack-solution) |
| 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/226.%20Invert%20Binary%20Tree.cpp) | Easy | Tree | [discuss](https://discuss.leetcode.com/topic/85926/clean-c-recursive-iterative-solution) |
| 227 | [Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/227.%20Basic%20Calculator%20II.cpp) | Medium | String | [discuss](https://discuss.leetcode.com/topic/98114/clean-16-lines-c-using-lambda) |
| 228 | [Summary Ranges](https://leetcode.com/problems/summary-ranges/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/228.%20Summary%20Ranges.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/108363/6-lines-c) |
| 229 | [Majority Element II](https://leetcode.com/problems/majority-element-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/229.%20Majority%20Element%20II.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/85914/c-12-ms-o-1-space-boyer-moore-majority-vote-algorithm) |
| 230 | [Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/230.%20Kth%20Smallest%20Element%20in%20a%20BST.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/80538/two-8-lines-solutions-in-c-easy-to-understand) |
| 231 | [Power of Two](https://leetcode.com/problems/power-of-two/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/231.%20Power%20of%20Two.cpp) | Easy | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/108365/one-line-c) |
| 234 | [Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/234.%20Palindrome%20Linked%20List.cpp) | Easy | Linked List / Two Pointers | [discuss](https://discuss.leetcode.com/topic/101317/clean-c-o-1-space) |
| 235 | [Lowest Common Ancestor of a Binary Search Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/235.%20Lowest%20Common%20Ancestor%20of%20a%20Binary%20Search%20Tree.cpp) | Easy | Tree | [discuss](https://discuss.leetcode.com/topic/86300/share-my-c-26ms-recursion) |
| 236 | [Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/236.%20Lowest%20Common%20Ancestor%20of%20a%20Binary%20Tree.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/79268/c-dfs-brute-force-solution) |
| 238 | [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/238.%20Product%20of%20Array%20Except%20Self.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/101324/c-o-n) |
| 239 | [Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/239.%20Sliding%20Window%20Maximum.cpp) | Hard |Heap | [discuss](https://discuss.leetcode.com/topic/77089/clean-c-62ms-solution-beats-98-22-no-extra-space) |
| 240 | [Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/240.%20Search%20a%202D%20Matrix%20II.cpp) | Medium | Binary Search / Divide and Conquer | [discuss](https://discuss.leetcode.com/topic/108479/two-c-solutions) |
| 244 | [Shortest Word Distance II](https://leetcode.com/problems/shortest-word-distance-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/244.%20Shortest%20Word%20Distance%20II.cpp) | Medium | Hash Table / Design | [discuss](https://leetcode.com/problems/shortest-word-distance-ii/discuss/121877/C++-O(n)-solution) |
| 246 | [Strobogrammatic Number](https://leetcode.com/problems/strobogrammatic-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/246.%20Strobogrammatic%20Number.cpp) | Easy | Hash Table / Math | [discuss](https://discuss.leetcode.com/topic/91838/7-lines-c-0ms) |
| 247 | [Strobogrammatic Number II](https://leetcode.com/problems/strobogrammatic-number-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/247.%20Strobogrammatic%20Number%20II.cpp) | Medium | Math / Recursion | [discuss](https://discuss.leetcode.com/topic/105993/c-recursion) |
| 249 | [Group Shifted Strings](https://leetcode.com/problems/group-shifted-strings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/249.%20Group%20Shifted%20Strings.cpp) | Medium | String | [discuss](https://discuss.leetcode.com/topic/105677/6ms-c-easy-to-understand) |
| 251 | [Flatten 2D Vector](https://leetcode.com/problems/flatten-2d-vector/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/247.%20Strobogrammatic%20Number%20II.cpp) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/104514/6-lines-c) |
| 252 | [Meeting Rooms](https://leetcode.com/problems/meeting-rooms/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/252.%20Meeting%20Rooms.cpp) | Easy | Sort | [discuss](https://discuss.leetcode.com/topic/88677/c-4-lines-concise-solution-using-lambda) |
| 253 | [Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/253.%20Meeting%20Rooms%20II.cpp) | Medium | Heap / Sort | [discuss](https://discuss.leetcode.com/topic/98299/c-11-lines-9ms-min-heap) |
| 255 | [Verify Preorder Sequence in Binary Search Tree](https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/255.%20Verify%20Preorder%20Sequence%20in%20Binary%20Search%20Tree.cpp) | Medium | Stack / Tree | [discuss](https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/discuss/116243/7-lines-C++-DandC) |
| 257 | [Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/257.%20Binary%20Tree%20Paths.cpp) | Easy | Tree / DFS / BFS | [discuss](https://discuss.leetcode.com/topic/87776/c-simple-12-lines-3ms-dfs) |
| 258 | [Add Digits](https://leetcode.com/problems/add-digits/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/258.%20Add%20Digits.cpp) | Easy | Math | [discuss](https://discuss.leetcode.com/topic/85916/1-line-c) |
| 259 | [3Sum Smaller](https://leetcode.com/problems/3sum-smaller/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/259.%203Sum%20Smaller.cpp) | Medium | Array / Two Pointers | [discuss](https://discuss.leetcode.com/topic/105684/8-lines-c-o-n-2) |
| 261 | [Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/261.%20Graph%20Valid%20Tree.cpp) | Medium | Graph / BFS / DFS / Union Find | [discuss](https://discuss.leetcode.com/topic/100516/clean-c-bfs-9ms-find-circle-in-graph) |
| 263 | [Ugly Number](https://leetcode.com/problems/ugly-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/263.%20Ugly%20Number.cpp) | Easy | Math | [discuss](https://discuss.leetcode.com/topic/102165/one-line-c) |
| 264 | [Ugly Number II](https://leetcode.com/problems/ugly-number-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/264.%20Ugly%20Number%20II.cpp) | Medium | Dynamic Programming / Math | [discuss](https://discuss.leetcode.com/topic/102172/10-lines-c) |
| 266 | [Palindrome Permutation](https://leetcode.com/problems/palindrome-permutation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/266.%20Palindrome%20Permutation.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/91044/4-lines-c-hash-table) |
| 267 | [Palindrome Permutation II](https://leetcode.com/problems/palindrome-permutation-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/267.%20Palindrome%20Permutation%20II.cpp) | Medium | Backtracking | [discuss](https://leetcode.com/problems/palindrome-permutation-ii/discuss/121889/3ms-C++-backtracking) |
| 268 | [Missing Number](https://leetcode.com/problems/missing-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/268.%20Missing%20Number.cpp) | Easy | Array / Bit Manipulation | [discuss](https://leetcode.com/problems/missing-number/discuss/131408/3-lines-C++) |
| 269 | [Alien Dictionary](https://leetcode.com/problems/alien-dictionary/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/269.%20Alien%20Dictionary.cpp) | Hard | Graph / Topological Sort | [discuss](https://discuss.leetcode.com/topic/107067/short-c-bfs-topological-sort) |
| 270 | [Closest Binary Search Tree Value](https://leetcode.com/problems/closest-binary-search-tree-value/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/270.%20Closest%20Binary%20Search%20Tree%20Value.cpp) | Easy | Tree / Binary Search | [discuss](https://discuss.leetcode.com/topic/108393/7-lines-c) |
| 271 | [Encode and Decode Strings](https://leetcode.com/problems/encode-and-decode-strings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/271.%20Encode%20and%20Decode%20Strings.cpp) | Medium | String / Design | [discuss](https://discuss.leetcode.com/topic/104401/c-encode-with) |
| 272 | [Closest Binary Search Tree Value II](https://leetcode.com/problems/closest-binary-search-tree-value-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/272.%20Closest%20Binary%20Search%20Tree%20Value%20II.cpp) | Hard | Tree / Stack | [discuss](https://discuss.leetcode.com/topic/109470/10-lines-c-o-nlogk-maxheap-solution) |
| 273 | [Integer to English Words](https://leetcode.com/problems/integer-to-english-words/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/273.%20Integer%20to%20English%20Words.cpp) | Hard | String | [discuss](https://discuss.leetcode.com/topic/104627/3ms-short-c) |
| 274 | [H-Index](https://leetcode.com/problems/h-index/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/274.%20H-Index.cpp) | Medium | Sort | [discuss](https://discuss.leetcode.com/topic/101496/4-lines-c) |
| 275 | [H-Index II](https://leetcode.com/problems/h-index-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/275.%20H-Index%20II.cpp) | Medium | Binary Search | [discuss](https://discuss.leetcode.com/topic/102873/c-3-lines-o-n-8-lines-binary-search-o-logn) |
| 276 | [Paint Fence](https://leetcode.com/problems/paint-fence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/276.%20Paint%20Fence.cpp) | Easy | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/91156/4-lines-c) |
| 277 | [Find the Celebrity](https://leetcode.com/problems/find-the-celebrity/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/277.%20Find%20the%20Celebrity.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/99937/c-o-n) |
| 278 | [First Bad Version](https://leetcode.com/problems/first-bad-version/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/278.%20First%20Bad%20Version.cpp) | Easy | Binary Search | [discuss](https://discuss.leetcode.com/topic/86885/c-5-lines-0ms-binary-search) |
| 279 | [Perfect Squares](https://leetcode.com/problems/perfect-squares/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/279.%20Perfect%20Squares.cpp) | Medium | Math / Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108483/c-6ms-static-dp) |
| 280 | [Wiggle Sort](https://leetcode.com/problems/wiggle-sort/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/280.%20Wiggle%20Sort.cpp) | Easy | Array | [discuss](https://discuss.leetcode.com/topic/97352/short-c) |
| 281 | [Zigzag Iterator](https://leetcode.com/problems/zigzag-iterator/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/281.%20Zigzag%20Iterator.cpp) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/104332/c-o-1-space-and-follow-up-for-k-vectors) |
| 282 | [Expression Add Operators](https://leetcode.com/problems/expression-add-operators/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/282.%20Expression%20Add%20Operators.cpp) | Hard | Divide and Conquer | [discuss](https://discuss.leetcode.com/topic/99983/c-backtracking) |
| 283 | [Move Zeroes](https://leetcode.com/problems/move-zeroes/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/283.%20Move%20Zeroes.cpp) | Easy | Array / Two Pointers | [discuss](https://discuss.leetcode.com/topic/85925/c-3-lines-solution) |
| 284 | [Peeking Iterator](https://leetcode.com/problems/peeking-iterator/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/284.%20Peeking%20Iterator.cpp) | Medum | Design | [discuss](https://discuss.leetcode.com/topic/105798/c-using-deque) |
| 285 | [Inorder Successor in BST](https://leetcode.com/problems/inorder-successor-in-bst/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/285.%20Inorder%20Successor%20in%20BST.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/100023/c-solution-for-any-binary-tree) |
| 286 | [Walls and Gates](https://leetcode.com/problems/walls-and-gates/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/286.%20Walls%20and%20Gates.cpp) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/100331/c-bfs-from-inf-or-0) |
| 289 | [Game of Life](https://leetcode.com/problems/game-of-life/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/289.%20Game%20of%20Life.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/95672/c-in-place-solution) |
| 290 | [Word Pattern](https://leetcode.com/problems/word-pattern/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/290.%20Word%20Pattern.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/107956/11-lines-c) |
| 293 | [Flip Game](https://leetcode.com/problems/flip-game/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/293.%20Flip%20Game.cpp) | Easy | String | [discuss](https://discuss.leetcode.com/topic/108535/8-lines-c) |
| 294 | [Flip Game II](https://leetcode.com/problems/flip-game-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/294.%20Flip%20Game%20II.cpp) | Medium | Backtracking | [discuss](https://discuss.leetcode.com/topic/108539/7-lines-c) |
| 295 | [Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/295.%20Find%20Median%20from%20Data%20Stream.cpp) | Hard | Heap / Design | [discuss](https://discuss.leetcode.com/topic/107631/c-two-heaps) |
| 297 | [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/297.%20Serialize%20and%20Deserialize%20Binary%20Tree.cpp) | Hard | Tree / Design | [discuss](https://discuss.leetcode.com/topic/99965/c-8-lines-cheat-solution-22-ms-beats-99-57) |
| 298 | [Binary Tree Longest Consecutive Sequence](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/298.%20Binary%20Tree%20Longest%20Consecutive%20Sequence.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/104321/short-c-8-lines-dfs-and-12-lines-bfs) |
| 300 | [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/300.%20Longest%20Increasing%20Subsequence.cpp) | Medium | Binary Search / Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/106903/short-c-o-n-2-dp-and-o-nlogn-binary-search) |
| 301 | [Remove Invalid Parentheses](https://leetcode.com/problems/remove-invalid-parentheses/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/301.%20Remove%20Invalid%20Parentheses.cpp) | Hard | Backtracking / DFS / BFS | [discuss](https://discuss.leetcode.com/topic/99881/c-backtrack-easy-to-understand) |
| 303 | [Range Sum Query - Immutable](https://leetcode.com/problems/range-sum-query-immutable/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/303.%20Range%20Sum%20Query%20-%20Immutable.cpp) | Easy | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104447/7-lines-c-dp) |
| 304 | [Range Sum Query 2D - Immutable](https://leetcode.com/problems/range-sum-query-2d-immutable/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/304.%20Range%20Sum%20Query%202D%20-%20Immutable.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104453/7-lines-c-dp) |
| 305 | [Number of Islands II](https://leetcode.com/problems/number-of-islands-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/305.%20Number%20of%20Islands%20II.cpp) | Hard | Union Find | [discuss](https://discuss.leetcode.com/topic/107415/clean-c-union-find) |
| 307 | [Range Sum Query - Mutable](https://leetcode.com/problems/range-sum-query-mutable/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/307.%20Range%20Sum%20Query%20-%20Mutable.cpp) | Medium | Segment Tree | [discuss](https://discuss.leetcode.com/topic/104511/c-749ms-brute-force) |
| 309 | [Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/309.%20Best%20Time%20to%20Buy%20and%20Sell%20Stock%20with%20Cooldown.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108594/share-my-6ms-c-dp-solution) |
| 310 | [Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/310.%20Minimum%20Height%20Trees.cpp) | Medium | BFS/ Graph | [discuss](https://discuss.leetcode.com/topic/100685/c-from-bf-1880ms-to-o-n-35ms-beats-99-with-explanation) |
| 311 | [Sparse Matrix Multiplication](https://leetcode.com/problems/sparse-matrix-multiplication/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/311.%20Sparse%20Matrix%20Multiplication.cpp) | Medium | Matrix | [discuss](https://discuss.leetcode.com/topic/98234/clean-10-lines-c) |
| 313 | [Super Ugly Number](https://leetcode.com/problems/super-ugly-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/313.%20Super%20Ugly%20Number.cpp) | Medium | Dynamic Programming / Math | [discuss](https://discuss.leetcode.com/topic/102178/clean-9-lines-c) |
| 314 | [Binary Tree Vertical Order Traversal](https://leetcode.com/problems/binary-tree-vertical-order-traversal/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/314.%20Binary%20Tree%20Vertical%20Order%20Traversal.cpp) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/99884/clean-3-ms-bfs-c) |
| 315 | [Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/315.%20Count%20of%20Smaller%20Numbers%20After%20Self.cpp) | Hard | Divide and Conqur / Binary Search Tree | [discuss](https://discuss.leetcode.com/topic/107641/c-bst) |
| 317 | [Shortest Distance from All Buildings](https://leetcode.com/problems/shortest-distance-from-all-buildings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/317.%20Shortest%20Distance%20from%20All%20Buildings.cpp) | Hard | BFS | [discuss](https://discuss.leetcode.com/topic/107548/clean-c-bfs) |
| 318 | [Maximum Product of Word Lengths](https://leetcode.com/problems/maximum-product-of-word-lengths/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/318.%20Maximum%20Product%20of%20Word%20Lengths.cpp) | Medium | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/97533/two-clean-solutions-c) |
| 323 | [Number of Connected Components in an Undirected Graph](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/323.%20Number%20of%20Connected%20Components%20in%20an%20Undirected%20Graph.cpp) | Medium | Graph / Union Find / BFS / DFS | [discuss](https://discuss.leetcode.com/topic/105915/c-dfs-and-bfs-solution) |
| 325 | [Maximum Size Subarray Sum Equals k](https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/325.%20Maximum%20Size%20Subarray%20Sum%20Equals%20k.cpp) | Medium | Array / Hash Table | [discuss](https://discuss.leetcode.com/topic/99871/10-lines-c-o-n) |
| 329 | [Longest Increasing Path in a Matrix](https://leetcode.com/problems/longest-increasing-path-in-a-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/329.%20Longest%20Increasing%20Path%20in%20a%20Matrix.cpp) | Hard | DFS / Memorization | [discuss](https://discuss.leetcode.com/topic/80223/clean-c-29ms-dp-solution-beats-96-39) |
| 331 | [Verify Preorder Serialization of a Binary Tree](https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/331.%20Verify%20Preorder%20Serialization%20of%20a%20Binary%20Tree.cpp) | Medium | Stack | [discuss](https://discuss.leetcode.com/topic/105906/6ms-c-using-stack) |
| 332 | [Reconstruct Itinerary](https://leetcode.com/problems/reconstruct-itinerary/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/332.%20Reconstruct%20Itinerary.cpp) | Medium | Graph / DFS | [discuss](https://discuss.leetcode.com/topic/107397/c-min-heap) |
| 333 | [Largest BST Subtree](https://leetcode.com/problems/largest-bst-subtree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/333.%20Largest%20BST%20Subtree.cpp) | Medium | Tree | [discuss](https://leetcode.com/problems/largest-bst-subtree/discuss/116233/9-lines-12ms-C++-O(n)-solution) |
| 334 | [Increasing Triplet Subsequence](https://leetcode.com/problems/increasing-triplet-subsequence/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/334.%20Increasing%20Triplet%20Subsequence.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/97462/straight-forward-c-o-n-time-o-1-space-with-comments) |
| 336 | [Palindrome Pairs](https://leetcode.com/problems/palindrome-pairs/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/336.%20Palindrome%20Pairs.cpp) | Hard | Hash Table / String / Trie | [discuss](https://discuss.leetcode.com/topic/107615/short-c-trie) |
| 339 | [Nested List Weight Sum](https://leetcode.com/problems/nested-list-weight-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/339.%20Nested%20List%20Weight%20Sum.cpp) | Easy | DFS | [discuss](https://leetcode.com/problems/nested-list-weight-sum/discuss/121963/Simple-5-lines-C++) |
| 340 | [Longest Substring with At Most K Distinct Characters](https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/340.%20Longest%20Substring%20with%20At%20Most%20K%20Distinct%20Characters.cpp) | Hard | Hash Table / String | [discuss](https://discuss.leetcode.com/topic/104376/easy-8-lines-c-o-n) |
| 341 | [Flatten Nested List Iterator](https://leetcode.com/problems/flatten-nested-list-iterator/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/341.%20Flatten%20Nested%20List%20Iterator.cpp) | Medium | Stack / Design | [discuss](https://discuss.leetcode.com/topic/97644/short-c-16ms-using-deque) |
| 344 | [Reverse String](https://leetcode.com/problems/reverse-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/344.%20Reverse%20String.cpp) | Easy | String | [discuss](https://discuss.leetcode.com/topic/77597/simple-c-9ms-solution) |
| 347 | [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/347.%20Top%20K%20Frequent%20Elements.cpp) | Medium | Hash Table / Heap | [discuss](https://discuss.leetcode.com/topic/95435/7-lines-c-o-nlogn-solutions-maxheap-minheap) |
| 348 | [Design Tic-Tac-Toe](https://leetcode.com/problems/design-tic-tac-toe/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/348.%20Design%20Tic-Tac-Toe.cpp) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/106788/26ms-c-easy-to-understand) |
| 351 | [Android Unlock Patterns](https://leetcode.com/problems/android-unlock-patterns/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/351.%20Android%20Unlock%20Patterns.cpp) | Medium | DFS / Dynamic Programming | [discuss](https://leetcode.com/problems/android-unlock-patterns/discuss/198845/C++-dfs-easy-to-understand) |
| 354 | [Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/354.%20Russian%20Doll%20Envelopes.cpp) | Hard | Binary Search / Dynamic Programming | [discuss](https://leetcode.com/problems/russian-doll-envelopes/discuss/134395/10-lines-C++) |
| 355 | [Design Twitter](https://leetcode.com/problems/design-twitter/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/355.%20Design%20Twitter.cpp) | Medium | Hash Table / Design | [discuss](https://discuss.leetcode.com/topic/82459/simple-11-lines-c-o-n-solution) |
| 359 | [Logger Rate Limiter](https://leetcode.com/problems/logger-rate-limiter/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/359.%20Logger%20Rate%20Limiter.cpp) | Easy | Hash Table / Design ||
| 360 | [Sort Transformed Array](https://leetcode.com/problems/sort-transformed-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/360.%20Sort%20Transformed%20Array.cpp) | Medium | Math / Two Pointers | [discuss](https://discuss.leetcode.com/topic/107606/short-c-o-n-easy-to-understand) |
| 361 | [Bomb Enemy](https://leetcode.com/problems/bomb-enemy/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/361.%20Bomb%20Enemy.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104340/clean-c-direction-based-solution) |
| 362 | [Design Hit Counter](https://leetcode.com/problems/design-hit-counter/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/362.%20Design%20Hit%20Counter.cpp) | Medium | Design | [discuss](https://discuss.leetcode.com/topic/105787/4-lines-c) |
| 364 | [Nested List Weight Sum II](https://leetcode.com/problems/nested-list-weight-sum-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/364.%20Nested%20List%20Weight%20Sum%20II.cpp) | Medium | DFS | [discuss](https://leetcode.com/problems/nested-list-weight-sum-ii/discuss/121967/10-lines-C++-recursion) |
| 369 | [Plus One Linked List](https://leetcode.com/problems/plus-one-linked-list/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/369.%20Plus%20One%20Linked%20List.cpp) | Medium | Linked List | [discuss](https://discuss.leetcode.com/topic/105864/simple-c-reverse-list-and-add) |
| 373 | [Find K Pairs with Smallest Sums](https://leetcode.com/problems/find-k-pairs-with-smallest-sums/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/373.%20Find%20K%20Pairs%20with%20Smallest%20Sums.cpp) | Medium | Heap | [discuss](https://discuss.leetcode.com/topic/106033/7-lines-c-minheap-and-maxheap) |
| 377 | [Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/377.%20Combination%20Sum%20IV.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/100273/c-recursion) |
| 378 | [Kth Smallest Element in a Sorted Matrix](https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/378.%20Kth%20Smallest%20Element%20in%20a%20Sorted%20Matrix.cpp) | Medium | Binary Search / Heap | [discuss](https://discuss.leetcode.com/topic/105997/5-lines-c-minheap-and-multiset) |
| 380 | [Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/380.%20Insert%20Delete%20GetRandom%20O(1).cpp) | Medium | Hash Table / Design | [discuss](https://discuss.leetcode.com/topic/104313/10-lines-c-92ms) |
| 382 | [Linked List Random Node](https://leetcode.com/problems/linked-list-random-node/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/382.%20Linked%20List%20Random%20Node.cpp) | Medium | Reservoir Sampling | [discuss](https://discuss.leetcode.com/topic/106031/c-reservoir-sampling) |
| 394 | [Decode String](https://leetcode.com/problems/decode-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/394.%20Decode%20String.cpp) | Medium | String / DFS | [discuss](https://discuss.leetcode.com/topic/104396/c-0ms-recursion) |
| 398 | [Random Pick Index](https://leetcode.com/problems/random-pick-index/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/398.%20Random%20Pick%20Index.cpp) | Medium | Reservoir Sampling | [discuss](https://discuss.leetcode.com/topic/101489/my-c-solutions) |
| 399 | [Evaluate Division](https://leetcode.com/problems/evaluate-division/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/399.%20Evaluate%20Division.cpp) | Medium | Graph | [discuss](https://discuss.leetcode.com/topic/105762/clean-3ms-c-bfs) |
| 402 | [Remove K Digits](https://leetcode.com/problems/remove-k-digits/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/402.%20Remove%20K%20Digits.cpp) | Medium | Greedy | [discuss](https://discuss.leetcode.com/topic/105966/my-c-o-n-solution) |
| 404 | [Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/404.%20Sum%20of%20Left%20Leaves.cpp) | Easy | Tree | [discuss](https://discuss.leetcode.com/topic/91207/2-lines-c-dfs) |
| 408 | [Valid Word Abbreviation](https://leetcode.com/problems/valid-word-abbreviation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/408.%20Valid%20Word%20Abbreviation.cpp) | Easy | String | [discuss](https://discuss.leetcode.com/topic/108894/short-c-solution) |
| 409 | [Longest Palindrome](https://leetcode.com/problems/longest-palindrome/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/409.%20Longest%20Palindrome.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/109840/4-lines-c) |
| 411 | [Minimum Unique Word Abbreviation](https://leetcode.com/problems/minimum-unique-word-abbreviation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/411.%20Minimum%20Unique%20Word%20Abbreviation.cpp) | Hard | Backtracking | [discuss](https://discuss.leetcode.com/topic/108917/c-dfs-solution-not-easy-to-understand) |
| 412 | [Fizz Buzz](https://leetcode.com/problems/fizz-buzz/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/412.%20Fizz%20Buzz.cpp) | Easy | Array | [discuss](https://discuss.leetcode.com/topic/85930/c-3ms) |
| 416 | [Partition Equal Subset Sum](https://leetcode.com/problems/partition-equal-subset-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/416.%20Partition%20Equal%20Subset%20Sum.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/108717/9-lines-c-dp) |
| 417 | [Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/417.%20Pacific%20Atlantic%20Water%20Flow.cpp) | Medium | DFS / BFS | [discuss](https://discuss.leetcode.com/topic/105705/c-dfs-easy-to-understand) |
| 418 | [Sentence Screen Fitting](https://leetcode.com/problems/sentence-screen-fitting/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/418.%20Sentence%20Screen%20Fitting.cpp) | Medium | Dynamic Programming ||
| 433 | [Minimum Genetic Mutation](https://leetcode.com/problems/minimum-genetic-mutation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/433.%20Minimum%20Genetic%20Mutation.cpp) | Medium | BFS | [discuss](https://discuss.leetcode.com/topic/101984/clean-c-bfs-same-as-word-ladder) |
| 435 | [Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/435.%20Non-overlapping%20Intervals.cpp) | Medium | Greedy | [discuss](https://leetcode.com/problems/non-overlapping-intervals/discuss/116085/11-lines-C++) |
| 436 | [Find Right Interval](https://leetcode.com/problems/find-right-interval/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/436.%20Find%20Right%20Interval.cpp) | Medium | Array / Binary Search | [discuss](https://leetcode.com/problems/find-right-interval/discuss/116073/8-lines-C++) |
| 438 | [Find All Anagrams in a String](https://leetcode.com/problems/find-all-anagrams-in-a-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/438.%20Find%20All%20Anagrams%20in%20a%20String.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/111121/12-lines-c-o-n-solution) |
| 441 | [Arranging Coins](https://leetcode.com/problems/arranging-coins/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/441.%20Arranging%20Coins.cpp) | Easy | Math | [discuss](https://discuss.leetcode.com/topic/92001/3-lines-c-easy-to-understand) |
| 444 | [Sequence Reconstruction](https://leetcode.com/problems/sequence-reconstruction/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/444.%20Sequence%20Reconstruction.cpp) | Medium | Graph / Topological Sort | [discuss](https://discuss.leetcode.com/topic/108886/short-c-topological-sort-solution-easy-to-understand) |
| 450 | [Delete Node in a BST](https://leetcode.com/problems/delete-node-in-a-bst/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/450.%20Delete%20Node%20in%20a%20BST.cpp) | Medium | Tree | [discuss](https://leetcode.com/problems/delete-node-in-a-bst/discuss/137641/10-lines-C++) |
| 451 | [Sort Characters By Frequency](https://leetcode.com/problems/sort-characters-by-frequency/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/451.%20Sort%20Characters%20By%20Frequency.cpp) | Medium | Hash Table / Heap | [discuss](https://discuss.leetcode.com/topic/106967/c-o-nlogn-hash-table-priority_queue) |
| 461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/461.%20Hamming%20Distance.cpp) | Easy | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/85931/4-lines-c-3ms) |
| 467 | [Unique Substrings in Wraparound String](https://leetcode.com/problems/unique-substrings-in-wraparound-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/467.%20Unique%20Substrings%20in%20Wraparound%20String.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/104587/9-lines-c) |
| 473 | [Matchsticks to Square](https://leetcode.com/problems/matchsticks-to-square/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/473.%20Matchsticks%20to%20Square.cpp) | Medium | DFS | [discuss](https://discuss.leetcode.com/topic/119716/c-17ms-dfs-solution) |
| 477 | [Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/477.%20Total%20Hamming%20Distance.cpp) | Medium | Bit Manipulation | [discuss](https://discuss.leetcode.com/topic/100420/7-lines-c-o-n) |
| 482 | [License Key Formatting](https://leetcode.com/problems/license-key-formatting/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/482.%20License%20Key%20Formatting.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/104317/9ms-straight-forward-c) |
| 484 | [Find Permutation](https://leetcode.com/problems/find-permutation/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/484.%20Find%20Permutation.cpp) | Medium | Greedy | [discuss](https://discuss.leetcode.com/topic/105887/9-lines-c) |
| 486 | [Predict the Winner](https://leetcode.com/problems/predict-the-winner/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/486.%20Predict%20the%20Winner.cpp) | Medium | Dynamic Programming / Minimax | [discuss](https://leetcode.com/problems/predict-the-winner/discuss/197984/C++-0ms-minimax) |
| 487 | [Max Consecutive Ones II](https://leetcode.com/problems/max-consecutive-ones-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/487.%20Max%20Consecutive%20Ones%20II.cpp) | Medium | Two Pointers | [discuss](https://leetcode.com/problems/max-consecutive-ones-ii/discuss/122406/7-lines-C++-two-pointers) |
| 489 | [Robot Room Cleaner](https://leetcode.com/problems/robot-room-cleaner/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/489.%20Robot%20Room%20Cleaner.cpp) | Hard | DFS | [discuss](https://leetcode.com/problems/robot-room-cleaner/discuss/199348/C++-dfs-easy-to-understand) |
| 490 | [The Maze](https://leetcode.com/problems/the-maze/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/490.%20The%20Maze.cpp) | Medium | BFS / DFS | |
| 494 | [Target Sum](https://leetcode.com/problems/target-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/494.%20Target%20Sum.cpp) | Medium | Backtracking | [discuss](https://discuss.leetcode.com/topic/100319/clean-c-backtrack-dp) |
| 496 | [Next Greater Element I](https://leetcode.com/problems/next-greater-element-i/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/496.%20Next%20Greater%20Element%20I.cpp) | Easy | Stack | [discuss](https://discuss.leetcode.com/topic/91234/c-o-n-time-o-1-space) |
| 498 | [Diagonal Traverse](https://leetcode.com/problems/diagonal-traverse/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/498.%20Diagonal%20Traverse.cpp) | Medium | Matrix | [discuss](https://discuss.leetcode.com/topic/105869/clean-c-recursion) |
| 499 | [The Maze III](https://leetcode.com/problems/the-maze-iii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/499.%20The%20Maze%20III.cpp) | Hard | DFS / BFS ||
| 503 | [Next Greater Element II](https://leetcode.com/problems/next-greater-element-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/503.%20Next%20Greater%20Element%20II.cpp) | Medium | Stack | [discuss](https://discuss.leetcode.com/topic/105963/c-from-o-n-2-to-o-n) |
| 505 | [The Maze II](https://leetcode.com/problems/the-maze-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/505.%20The%20Maze%20II.cpp) | Medium | DFS / BFS | [discuss](https://discuss.leetcode.com/topic/104907/c-dfs-direction-based-solution) |
| 508 | [Most Frequent Subtree Sum](https://leetcode.com/problems/most-frequent-subtree-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/508.%20Most%20Frequent%20Subtree%20Sum.cpp) | Medium | Tree / Hash Table | [discuss](https://discuss.leetcode.com/topic/109583/concise-c-13ms-o-n-solution) |
| 513 | [Find Bottom Left Tree Value](https://leetcode.com/problems/find-bottom-left-tree-value/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/513.%20Find%20Bottom%20Left%20Tree%20Value.cpp) | Medium | Tree / BFS / DFS | [discuss](https://discuss.leetcode.com/topic/109496/8-lines-c-dfs-solution) |
| 515 | [Find Largest Value in Each Tree Row](https://leetcode.com/problems/find-largest-value-in-each-tree-row/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/515.%20Find%20Largest%20Value%20in%20Each%20Tree%20Row.cpp) | Medium | Tree / BFS / DFS | [discuss](https://discuss.leetcode.com/topic/109495/c-bfs-and-dfs-solutions) |
| 523 | [Continuous Subarray Sum](https://leetcode.com/problems/continuous-subarray-sum/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/523.%20Continuous%20Subarray%20Sum.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/101395/share-my-not-too-long-c-solution) |
| 524 | [Longest Word in Dictionary through Deleting](https://leetcode.com/problems/longest-word-in-dictionary-through-deleting/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/524.%20Longest%20Word%20in%20Dictionary%20through%20Deleting.cpp) | Medium | Two Pointers | [discuss](https://discuss.leetcode.com/topic/105780/simple-c-move-pointers-beats-90) |
| 525 | [Contiguous Array](https://leetcode.com/problems/contiguous-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/525.%20Contiguous%20Array.cpp) | Medium | Hash Table | [discuss](https://discuss.leetcode.com/topic/100412/10-lines-c) |
| 531 | [Lonely Pixel I](https://leetcode.com/problems/lonely-pixel-i/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/531.%20Lonely%20Pixel%20I.cpp) | Medium | Array / DFS | [discuss](https://discuss.leetcode.com/topic/107379/simple-c-56ms-99-62) |
| 535 | [Encode and Decode TinyURL](https://leetcode.com/problems/encode-and-decode-tinyurl/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/535.%20Encode%20and%20Decode%20TinyURL.cpp) | Medium | String | [discuss](https://discuss.leetcode.com/topic/101377/short-c) |
| 536 | [Construct Binary Tree from String](https://leetcode.com/problems/construct-binary-tree-from-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/536.%20Construct%20Binary%20Tree%20from%20String.cpp) | Medium | String / Tree | [discuss](https://discuss.leetcode.com/topic/104659/short-c-recursive) |
| 538 | [Convert BST to Greater Tree](https://leetcode.com/problems/convert-bst-to-greater-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/538.%20Convert%20BST%20to%20Greater%20Tree.cpp) | Easy | DFS | [discuss](https://discuss.leetcode.com/topic/100522/7-lines-c-dfs) |
| 540 | [Single Element in a Sorted Array](https://leetcode.com/problems/single-element-in-a-sorted-array/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/540.%20Single%20Element%20in%20a%20Sorted%20Array.cpp) | Medium | Array / Binary Search | [discuss](https://discuss.leetcode.com/topic/100529/c-9-lines-binary-seach) |
| 541 | [Reverse String II](https://leetcode.com/problems/reverse-string-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/542.%2001%20Matrix.cpp) | Easy | String | [discuss](https://leetcode.com/problems/reverse-string-ii/discuss/129632/4-lines-C++) |
| 542 | [01 Matrix](https://leetcode.com/problems/01-matrix/description/) | [C++](https://github.com/fengvyi/LeetCode/blob/master/C%2B%2B/542.%2001%20Matrix.cpp) | Medium | BFS / DFS | [discuss](https://discuss.leetcode.com/topic/105984/c-bfs) |
| 543 | [Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/543.%20Diameter%20of%20Binary%20Tree.cpp) | Easy | Tree | [discuss](https://discuss.leetcode.com/topic/94276/c-6-lines-dfs) |
| 547 | [Friend Circles](https://leetcode.com/problems/friend-circles/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/547.%20Friend%20Circles.cpp) | Medium | DFS / Union Find | [discuss](https://discuss.leetcode.com/topic/100552/c-26ms-dfs-easy-to-understand) |
| 549 | [Binary Tree Longest Consecutive Sequence II](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/549.%20Binary%20Tree%20Longest%20Consecutive%20Sequence%20II.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/107340/13-lines-c-post-order-traversal) |
| 554 | [Brick Wall](https://leetcode.com/problems/brick-wall/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/554.%20Brick%20Wall.cpp) | Medium | Hash Table | [discuss](https://discuss.leetcode.com/topic/100401/c-hash-table-easy-to-understand) |
| 556 | [Next Greater Element III](https://leetcode.com/problems/next-greater-element-iii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/556.%20Next%20Greater%20Element%20III.cpp) | Medium | String ||
| 560 | [Subarray Sum Equals K](https://leetcode.com/problems/subarray-sum-equals-k/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/560.%20Subarray%20Sum%20Equals%20K.cpp) | Medium | Array / Map | [discuss](https://discuss.leetcode.com/topic/100697/simple-9-lines-c) |
| 562 | [Longest Line of Consecutive One in Matrix](https://leetcode.com/problems/longest-line-of-consecutive-one-in-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/562.%20Longest%20Line%20of%20Consecutive%20One%20in%20Matrix.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/106782/share-my-12-lines-c) |
| 565 | [Array Nesting](https://leetcode.com/problems/array-nesting/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/565.%20Array%20Nesting.cpp) | Medium | Array | [discuss](https://discuss.leetcode.com/topic/100545/c-29ms-dfs-o-n) |
| 566 | [Reshape the Matrix](https://leetcode.com/problems/reshape-the-matrix/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/566.%20Reshape%20the%20Matrix.cpp) | Easy | Array | [discuss](https://discuss.leetcode.com/topic/92281/c-easy-to-understand-beats-90-72) |
| 567 | [Permutation in String](https://leetcode.com/problems/permutation-in-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/567.%20Permutation%20in%20String.cpp) | Medium | Two Pointers | [discuss](https://leetcode.com/problems/permutation-in-string/discuss/133527/12-lines-C++) |
| 572 | [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/572.%20Subtree%20of%20Another%20Tree.cpp) | Easy | Tree | [discuss](https://discuss.leetcode.com/topic/101381/6-lines-c-dfs) |
| 582 | [Kill Process](https://leetcode.com/problems/kill-process/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/582.%20Kill%20Process.cpp) | Medium | Tree / BFS / DFS | [discuss](https://discuss.leetcode.com/topic/109587/c-bfs-and-dfs-solutions) |
| 583 | [Delete Operation for Two Strings](https://leetcode.com/problems/delete-operation-for-two-strings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/583.%20Delete%20Operation%20for%20Two%20Strings.cpp) | Medium | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/101563/c-6-lines-dp) |
| 599 | [Minimum Index Sum of Two Lists](https://leetcode.com/problems/minimum-index-sum-of-two-lists/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/599.%20Minimum%20Index%20Sum%20of%20Two%20Lists.cpp) | Easy | Hash Table | [discuss](https://discuss.leetcode.com/topic/92782/c-9-lines-hash-table-easy-to-understand) |
| 606 | [Construct String from Binary Tree](https://leetcode.com/problems/construct-string-from-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/606.%20Construct%20String%20from%20Binary%20Tree.cpp) | Easy | Tree / String | [discuss](https://discuss.leetcode.com/topic/93023/6-lines-c-recursion) |
| 611 | [Valid Triangle Number](https://leetcode.com/problems/valid-triangle-number/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/611.%20Valid%20Triangle%20Number.cpp) | Medium | Array | [discuss](https://leetcode.com/problems/valid-triangle-number/discuss/122396/7-lines-C++-brute-force) |
| 616 | [Add Bold Tag in String](https://leetcode.com/problems/add-bold-tag-in-string/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/616.%20Add%20Bold%20Tag%20in%20String.cpp) | Medium | String | [disucss](https://discuss.leetcode.com/topic/105757/c-trie) |
| 621 | [Task Scheduler](https://leetcode.com/problems/task-scheduler/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/621.%20Task%20Scheduler.cpp) | Medium | Array / Queue | [discuss](https://discuss.leetcode.com/topic/100438/c-priority_queue) |
| 632 | [Smallest Range](https://leetcode.com/problems/smallest-range/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/632.%20Smallest%20Range.cpp) | Hard | Two Pointers | [discuss](https://discuss.leetcode.com/topic/108083/c-min-heap) |
| 633 | [Sum of Square Numbers](https://leetcode.com/problems/sum-of-square-numbers/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/633.%20Sum%20of%20Square%20Numbers.cpp) | Easy | Math | [discuss](https://discuss.leetcode.com/topic/112742/3-lines-c-o-sqrt-n-solution) |
| 635 | [Design Log Storage System](https://leetcode.com/problems/design-log-storage-system/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/635.%20Design%20Log%20Storage%20System.cpp) | Medium | String / Design | [discuss](https://leetcode.com/problems/design-log-storage-system/discuss/137402/12-lines-C++) |
| 636 | [Exclusive Time of Functions](https://leetcode.com/problems/exclusive-time-of-functions/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/636.%20Exclusive%20Time%20of%20Functions.cpp) | Medium | Stack | [discuss](https://discuss.leetcode.com/topic/104296/clear-c-stack-easy-to-understand) |
| 637 | [Average of Levels in Binary Tree](https://leetcode.com/problems/average-of-levels-in-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/637.%20Average%20of%20Levels%20in%20Binary%20Tree.cpp) | Easy | BFS | [discuss](https://discuss.leetcode.com/topic/100446/c-typical-bfs) |
| 639 | [Decode Ways II](https://leetcode.com/problems/decode-ways-ii/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/639.%20Decode%20Ways%20II.cpp) | Hard | Dynamic Programming | [discuss](https://discuss.leetcode.com/topic/103455/c-59ms-ac-solution-feel-the-power-of-if-else) |
| 642 | [Design Search Autocomplete System](https://leetcode.com/problems/design-search-autocomplete-system/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/642.%20Design%20Search%20Autocomplete%20System.cpp) | Hard | Design / Trie | [discuss](https://leetcode.com/problems/design-search-autocomplete-system/discuss/133933/C++-Trie-and-priority_queue) |
| 643 | [Maximum Average Subarray I](https://leetcode.com/problems/maximum-average-subarray-i/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/643.%20Maximum%20Average%20Subarray%20I.cpp) | Easy | Array | [discuss](https://discuss.leetcode.com/topic/109366/simple-c-o-n-solution) |
| 645 | [Set Mismatch](https://leetcode.com/problems/set-mismatch/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/645.%20Set%20Mismatch.cpp) | Easy | Hash Table / Math | [discuss](https://discuss.leetcode.com/topic/119656/5-lines-c)
| 647 | [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/647.%20Palindromic%20Substrings.cpp) | Medium | String | [discuss](https://discuss.leetcode.com/topic/101542/8-lines-c-bf) |
| 648 | [Replace Words](https://leetcode.com/problems/replace-words/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/648.%20Replace%20Words.cpp) | Medium | Hash Table / Trie | [discuss](https://discuss.leetcode.com/topic/119431/14-lines-c-with-hash-table) |
| 652 | [Find Duplicate Subtrees](https://leetcode.com/problems/find-duplicate-subtrees/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/652.%20Find%20Duplicate%20Subtrees.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/107155/8-lines-c) |
| 653 | [Two Sum IV - Input is a BST](https://leetcode.com/problems/two-sum-iv-input-is-a-bst/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/653.%20Two%20Sum%20IV%20-%20Input%20is%20a%20BST.cpp) | Easy | DFS | [discuss](https://discuss.leetcode.com/topic/100517/6-lines-c) |
| 654 | [Maximum Binary Tree](https://leetcode.com/problems/maximum-binary-tree/description/) | [C++](https://github.com/rajeev-ranjan-au6/Leetcode_Cpp/blob/master/654.%20Maximum%20Binary%20Tree.cpp) | Medium | Tree | [discuss](https://discuss.leetcode.com/topic/107709/8-lines-c-recursion) |
| 657 | [Judge Route Circle](https://leetcode.com/problems/judge-route-circle/description/)