https://github.com/0voice/awesome-interview-algorithms
2025精选：算法题库合集，涵盖大厂面试、校招笔试及LeetCode等热门平台经典题目。附解法、指南与资源，助你轻松拿下offer！
https://github.com/0voice/awesome-interview-algorithms
List: awesome-interview-algorithms
algorithms awesome awesome-list coding-interview data-structures data-structures-and-algorithms interview-preparation leetcode
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2025精选：算法题库合集，涵盖大厂面试、校招笔试及LeetCode等热门平台经典题目。附解法、指南与资源，助你轻松拿下offer！
- Host: GitHub
- URL: https://github.com/0voice/awesome-interview-algorithms
- Owner: 0voice
- License: mit
- Created: 2025-11-03T06:55:50.000Z (about 2 months ago)
- Default Branch: main
- Last Pushed: 2025-11-08T07:23:37.000Z (about 2 months ago)
- Last Synced: 2025-11-08T09:12:39.430Z (about 2 months ago)
- Topics: algorithms, awesome, awesome-list, coding-interview, data-structures, data-structures-and-algorithms, interview-preparation, leetcode
- Homepage:
- Size: 488 KB
- Stars: 7
- Watchers: 0
- Forks: 0
- Open Issues: 0
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Metadata Files:
- Readme: README.en.md
- License: LICENSE
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README
# 📁 2025 Latest Big Tech Algorithm Questions Collection
A curated list of high-frequency LeetCode problems for Big Tech interviews✨
[中文版 README](README.md)
## 🧭 Quick Navigation
[Big Tech Algorithm Questions](#-big-tech-algorithm-questions)
[Practice Platforms](#-practice-platforms)
[Resource Notes](#-resource-notes)
[Contribution Guidelines](#-contribution-guidelines)
## 🧠 Big Tech Algorithm Questions
### Notes:
- All questions in this README use **LeetCode original problem names + links** for direct practice.
- **Practice Suggestions**: Prioritize **LeetCode Hot 100**, and questions in this README with **High frequency**, covering 80% of big tech exam points.
- **Understand Big Tech Question Preferences and Variants**: Visit the [variants](https://github.com/0voice/Awesome-BigTech-Algorithms/blob/main/variants/README.md) folder.
- **Self-Practice**: Refer to the [Practice Platforms](#-practice-platforms) below.
### Big Tech Practice Navigation
- [ByteDance](#bytedance)
- [Alibaba](#alibaba)
- [Tencent](#tencent)
- [Meituan](#meituan)
- [Baidu](#baidu)
- [JD.com](#jdcom)
- [Huawei](#huawei)
- [Xiaomi](#xiaomi)
- [Microsoft](#microsoft)
- [Didi](#didi)
- [Ctrip](#ctrip)
- [Pinduoduo](#pinduoduo)
- [Xiaohongshu](#xiaohongshu)
- [vivo](#vivo)
- [OPPO](#oppo)
- [Ant Group](#ant-group)
- [iFlytek](#iflytek)
### ByteDance
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Valid Anagram | Hash Table, String | Easy | Medium | [LeetCode 242](https://leetcode.cn/problems/valid-anagram/) |
| Fizz Buzz | Math, String | Easy | Low | [LeetCode 412](https://leetcode.cn/problems/fizz-buzz/) |
| Reverse String | Array, Two Pointers | Easy | Low | [LeetCode 344](https://leetcode.cn/problems/reverse-string/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.cn/problems/valid-parentheses/) |
| Reverse Linked List | Linked List, Recursion | Easy | High | [LeetCode 206](https://leetcode.cn/problems/reverse-linked-list/) |
| Merge Two Sorted Lists | Linked List, Recursion | Easy | Medium | [LeetCode 21](https://leetcode.cn/problems/merge-two-sorted-lists/) |
| Remove Element | Array, Two Pointers | Easy | Medium | [LeetCode 27](https://leetcode.cn/problems/remove-element/) |
| Best Time to Buy and Sell Stock | Array, Dynamic Programming | Easy | High | [LeetCode 121](https://leetcode.cn/problems/best-time-to-buy-and-sell-stock/) |
| Reverse Integer | Math | Easy | Medium | [LeetCode 7](https://leetcode.cn/problems/reverse-integer/) |
| Palindrome Number | Math | Easy | Medium | [LeetCode 9](https://leetcode.cn/problems/palindrome-number/) |
| Roman to Integer | Hash Table, String | Easy | Low | [LeetCode 13](https://leetcode.cn/problems/roman-to-integer/) |
| Contains Duplicate | Array, Hash Table | Easy | High | [LeetCode 217](https://leetcode.cn/problems/contains-duplicate/) |
| Majority Element | Array, Divide and Conquer | Easy | High | [LeetCode 169](https://leetcode.cn/problems/majority-element/) |
| Linked List Cycle | Linked List, Two Pointers | Easy | Medium | [LeetCode 141](https://leetcode.cn/problems/linked-list-cycle/) |
| Climbing Stairs | Dynamic Programming | Easy | High | [LeetCode 70](https://leetcode.cn/problems/climbing-stairs/) |
| Remove Duplicates from Sorted List | Linked List | Easy | Low | [LeetCode 83](https://leetcode.cn/problems/remove-duplicates-from-sorted-list/) |
| Search a 2D Matrix | Array, Binary Search | Medium | Medium | [LeetCode 74](https://leetcode.cn/problems/search-a-2d-matrix/) |
| Add Two Numbers | Linked List, Math | Medium | High | [LeetCode 2](https://leetcode.cn/problems/add-two-numbers/) |
| Longest Substring Without Repeating Characters | Hash Table, String, Sliding Window | Medium | High | [LeetCode 3](https://leetcode.cn/problems/longest-substring-without-repeating-characters/) |
| Number of Islands | Depth-First Search, Breadth-First Search, Union Find | Medium | High | [LeetCode 200](https://leetcode.cn/problems/number-of-islands/) |
| Maximum Subarray | Array, Divide and Conquer, Dynamic Programming | Medium | High | [LeetCode 53](https://leetcode.cn/problems/maximum-subarray/) |
| Unique Paths | Dynamic Programming | Medium | Medium | [LeetCode 62](https://leetcode.cn/problems/unique-paths/) |
| Generate Parentheses | Backtracking | Medium | High | [LeetCode 22](https://leetcode.cn/problems/generate-parentheses/) |
| Remove Nth Node From End of List | Linked List, Two Pointers | Medium | High | [LeetCode 19](https://leetcode.cn/problems/remove-nth-node-from-end-of-list/) |
| Letter Combinations of a Phone Number | Backtracking, String | Medium | Medium | [LeetCode 17](https://leetcode.cn/problems/letter-combinations-of-a-phone-number/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.cn/problems/3sum/) |
| Permutations | Backtracking | Medium | High | [LeetCode 46](https://leetcode.cn/problems/permutations/) |
| Combination Sum | Backtracking | Medium | High | [LeetCode 39](https://leetcode.cn/problems/combination-sum/) |
| Group Anagrams | Array, Hash Table, String | Medium | Medium | [LeetCode 49](https://leetcode.cn/problems/group-anagrams/) |
| Merge Intervals | Array, Sorting | Medium | High | [LeetCode 56](https://leetcode.cn/problems/merge-intervals/) |
| Subsets | Bit Manipulation, Backtracking | Medium | Medium | [LeetCode 78](https://leetcode.cn/problems/subsets/) |
| Word Search | Array, Backtracking, Matrix | Medium | Low | [LeetCode 79](https://leetcode.cn/problems/word-search/) |
| Validate Binary Search Tree | Tree, Depth-First Search | Medium | Medium | [LeetCode 98](https://leetcode.cn/problems/validate-binary-search-tree/) |
| Construct Binary Tree from Preorder and Inorder Traversal | Tree, Array, Hash Table, Divide and Conquer | Medium | Medium | [LeetCode 105](https://leetcode.cn/problems/construct-binary-tree-from-preorder-and-inorder-traversal/) |
| Longest Consecutive Sequence | Union Find, Array, Hash Table | Medium | High | [LeetCode 128](https://leetcode.cn/problems/longest-consecutive-sequence/) |
| Word Break | Dynamic Programming, Memoization | Medium | Medium | [LeetCode 139](https://leetcode.cn/problems/word-break/) |
| Restore IP Addresses | String, Backtracking | Medium | Medium | [LeetCode 93](https://leetcode.cn/problems/restore-ip-addresses/) |
| LRU Cache | Hash Table, Doubly Linked List, Design | Medium | High | [LeetCode 146](https://leetcode.cn/problems/lru-cache/) |
| Valid Sudoku | Array, Hash Table, Backtracking, Matrix | Medium | Low | [LeetCode 36](https://leetcode.cn/problems/valid-sudoku/) |
| Two Sum II - Input Array Is Sorted | Array, Two Pointers | Medium | Medium | [LeetCode 167](https://leetcode.cn/problems/two-sum-ii-input-array-is-sorted/) |
| String to Integer (atoi) | String | Medium | Low | [LeetCode 8](https://leetcode.cn/problems/string-to-integer-atoi/) |
| Container With Most Water | Array, Two Pointers | Medium | High | [LeetCode 11](https://leetcode.cn/problems/container-with-most-water/) |
| Minimum Size Subarray Sum | Array, Prefix Sum, Two Pointers | Medium | Medium | [LeetCode 209](https://leetcode.cn/problems/minimum-size-subarray-sum/) |
| Next Permutation | Array | Medium | Medium | [LeetCode 31](https://leetcode.cn/problems/next-permutation/) |
| Spiral Matrix | Array, Matrix | Medium | Low | [LeetCode 54](https://leetcode.cn/problems/spiral-matrix/) |
| Search in Rotated Sorted Array | Array, Binary Search | Medium | High | [LeetCode 33](https://leetcode.cn/problems/search-in-rotated-sorted-array/) |
| Minimum Path Sum | Array, Dynamic Programming, Matrix | Medium | Medium | [LeetCode 64](https://leetcode.cn/problems/minimum-path-sum/) |
| Redundant Connection | Depth-First Search, Breadth-First Search, Union Find, Graph | Medium | Low | [LeetCode 684](https://leetcode.cn/problems/redundant-connection/) |
| Longest Mountain in Array | Array | Medium | Low | [LeetCode 845](https://leetcode.cn/problems/longest-mountain-in-array/) |
| Count Nice Pairs in an Array | Hash Table, String, Counting | Medium | Low | [LeetCode 1815](https://leetcode.cn/problems/count-nice-pairs-in-an-array/) |
| Subarray Sum Equals K | Array, Hash Table, Prefix Sum | Medium | High | [LeetCode 560](https://leetcode.cn/problems/subarray-sum-equals-k/) |
| Longest Palindromic Substring | String, Dynamic Programming | Medium | High | [LeetCode 5](https://leetcode.cn/problems/longest-palindromic-substring/) |
| Binary Tree Level Order Traversal | Tree, Breadth-First Search, Binary Tree | Medium | Medium | [LeetCode 102](https://leetcode.cn/problems/binary-tree-level-order-traversal/) |
| Course Schedule | Depth-First Search, Breadth-First Search, Graph, Topological Sort | Medium | Medium | [LeetCode 207](https://leetcode.cn/problems/course-schedule/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.cn/problems/kth-largest-element-in-an-array/) |
| Product of Array Except Self | Array, Prefix Sum | Medium | High | [LeetCode 238](https://leetcode.cn/problems/product-of-array-except-self/) |
| Longest Increasing Subsequence | Array, Dynamic Programming, Binary Search | Medium | High | [LeetCode 300](https://leetcode.cn/problems/longest-increasing-subsequence/) |
| Partition Equal Subset Sum | Dynamic Programming, Knapsack | Medium | Medium | [LeetCode 416](https://leetcode.cn/problems/partition-equal-subset-sum/) |
| Edit Distance | Dynamic Programming | Medium | Medium | [LeetCode 72](https://leetcode.cn/problems/edit-distance/) |
| Sliding Window Maximum | Queue, Sliding Window, Heap | Hard | High | [LeetCode 239](https://leetcode.cn/problems/sliding-window-maximum/) |
| Largest Component Size by Common Factor | Union Find, Array, Hash Table, Math | Hard | Low | [LeetCode 952](https://leetcode.cn/problems/largest-component-size-by-common-factor/) |
| Making A Large Island | Depth-First Search, Breadth-First Search, Matrix | Hard | Low | [LeetCode 827](https://leetcode.cn/problems/making-a-large-island/) |
| Median of Two Sorted Arrays | Array, Binary Search, Divide and Conquer | Hard | High | [LeetCode 4](https://leetcode.cn/problems/median-of-two-sorted-arrays/) |
| Merge k Sorted Lists | Linked List, Divide and Conquer, Heap, Priority Queue | Hard | High | [LeetCode 23](https://leetcode.cn/problems/merge-k-sorted-lists/) |
| Split Array Largest Sum | Array, Binary Search, Dynamic Programming | Hard | Medium | [LeetCode 410](https://leetcode.cn/problems/split-array-largest-sum/) |
| Reverse Nodes in k-Group | Linked List, Recursion | Hard | High | [LeetCode 25](https://leetcode.cn/problems/reverse-nodes-in-k-group/) |
| Profitable Schemes | Dynamic Programming | Hard | Medium | [LeetCode 879](https://leetcode.cn/problems/profitable-schemes/) |
| Maximum Profit in Job Scheduling | Array, Binary Search, Dynamic Programming, Sorting | Hard | Medium | [LeetCode 1235](https://leetcode.cn/problems/maximum-profit-in-job-scheduling/) |
| Trapping Rain Water | Stack, Array, Two Pointers, Dynamic Programming, Monotonic Stack | Hard | High | [LeetCode 42](https://leetcode.cn/problems/trapping-rain-water/) |
| Minimum Window Substring | Hash Table, String, Sliding Window | Hard | High | [LeetCode 76](https://leetcode.cn/problems/minimum-window-substring/) |
| Largest Rectangle in Histogram | Array, Stack, Monotonic Stack | Hard | High | [LeetCode 84](https://leetcode.cn/problems/largest-rectangle-in-histogram/) |
| Binary Tree Maximum Path Sum | Tree, Depth-First Search, Dynamic Programming, Binary Tree | Hard | High | [LeetCode 124](https://leetcode.cn/problems/binary-tree-maximum-path-sum/) |
### Alibaba
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Two Sum | Array, Hash Table | Easy | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Stack, String | Easy | Medium | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Reverse Linked List | Linked List, Recursion | Easy | High | [LeetCode 206](https://leetcode.com/problems/reverse-linked-list/) |
| Climbing Stairs | Dynamic Programming, Memoization | Easy | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Best Time to Buy and Sell Stock | Array, Dynamic Programming | Easy | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Maximum Subarray | Array, Greedy | Easy | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Convert Sorted Array to Binary Search Tree | Tree, Depth-First Search | Easy | Medium | [LeetCode 108](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/) |
| Minimum Depth of Binary Tree | Tree, Depth-First Search | Easy | Low | [LeetCode 111](https://leetcode.com/problems/minimum-depth-of-binary-tree/) |
| Invert Binary Tree | Tree, Depth-First Search | Easy | High | [LeetCode 226](https://leetcode.com/problems/invert-binary-tree/) |
| Path Sum | Tree, Depth-First Search | Easy | Medium | [LeetCode 112](https://leetcode.com/problems/path-sum/) |
| Implement strStr() | String, Sliding Window | Easy | Low | [LeetCode 28](https://leetcode.com/problems/implement-strstr/) |
| Search Insert Position | Array, Binary Search | Easy | Medium | [LeetCode 35](https://leetcode.com/problems/search-insert-position/) |
| Maximum Depth of Binary Tree | Tree, Depth-First Search | Easy | Medium | [LeetCode 104](https://leetcode.com/problems/maximum-depth-of-binary-tree/) |
| Kth Missing Positive Number | Array, Math | Easy | Low | [LeetCode 1539](https://leetcode.com/problems/kth-missing-positive-number/) |
| Find Smallest Letter Greater Than Target | Array, Binary Search | Easy | Low | [LeetCode 744](https://leetcode.com/problems/find-smallest-letter-greater-than-target/) |
| Longest Substring Without Repeating Characters | String, Two Pointers | Medium | High | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Number of Islands | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Course Schedule | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Coin Change | Dynamic Programming | Medium | High | [LeetCode 322](https://leetcode.com/problems/coin-change/) |
| Decode String | Stack, Recursion | Medium | Medium | [LeetCode 394](https://leetcode.com/problems/decode-string/) |
| Add Strings | String, Math | Medium | Low | [LeetCode 415](https://leetcode.com/problems/add-strings/) |
| Find All Anagrams in a String | Hash Table, Sliding Window | Medium | Medium | [LeetCode 438](https://leetcode.com/problems/find-all-anagrams-in-a-string/) |
| Diameter of Binary Tree | Tree, Depth-First Search | Medium | Medium | [LeetCode 543](https://leetcode.com/problems/diameter-of-binary-tree/) |
| Daily Temperatures | Stack, Monotonic Stack | Medium | Medium | [LeetCode 739](https://leetcode.com/problems/daily-temperatures/) |
| Partition Labels | Greedy, Two Pointers | Medium | Low | [LeetCode 763](https://leetcode.com/problems/partition-labels/) |
| K Closest Points to Origin | Sorting, Heap | Medium | Low | [LeetCode 973](https://leetcode.com/problems/k-closest-points-to-origin/) |
| Merge k Sorted Lists | Linked List, Divide and Conquer | Medium | Medium | [LeetCode 23](https://leetcode.com/problems/merge-k-sorted-lists/) |
| Longest Valid Parentheses | Stack, Dynamic Programming | Medium | Medium | [LeetCode 32](https://leetcode.com/problems/longest-valid-parentheses/) |
| Jump Game | Greedy | Medium | Medium | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Unique Paths | Dynamic Programming | Medium | Medium | [LeetCode 62](https://leetcode.com/problems/unique-paths/) |
| Course Schedule II | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 210](https://leetcode.com/problems/course-schedule-ii/) |
| Lowest Common Ancestor of a Binary Tree | Tree, Depth-First Search | Medium | High | [LeetCode 236](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/) |
| Custom Sort String | String, Greedy | Medium | Low | [LeetCode 791](https://leetcode.com/problems/custom-sort-string/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Find Duplicate Subtrees | Tree, Hash Table | Medium | Low | [LeetCode 652](https://leetcode.com/problems/find-duplicate-subtrees/) |
| Validate Binary Search Tree | Tree, Depth-First Search | Medium | High | [LeetCode 98](https://leetcode.com/problems/validate-binary-search-tree/) |
| Construct Binary Tree from Preorder and Inorder Traversal | Tree, Array | Medium | Medium | [LeetCode 105](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/) |
| Construct Binary Tree from Inorder and Postorder Traversal | Tree, Array | Medium | Medium | [LeetCode 106](https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/) |
| Kth Smallest Element in a BST | Tree, Depth-First Search | Medium | Medium | [LeetCode 230](https://leetcode.com/problems/kth-smallest-element-in-a-bst/) |
| Path Sum II | Tree, Depth-First Search | Medium | Medium | [LeetCode 113](https://leetcode.com/problems/path-sum-ii/) |
| Binary Tree Right Side View | Tree, Depth-First Search | Medium | Medium | [LeetCode 199](https://leetcode.com/problems/binary-tree-right-side-view/) |
| Partition Equal Subset Sum | DP, Subset Sum | Medium | High | [LeetCode 416](https://leetcode.com/problems/partition-equal-subset-sum/) |
| Can I Win | DP, State Compression | Medium | Low | [LeetCode 464](https://leetcode.com/problems/can-i-win/) |
| Maximum Sum Circular Subarray | Probability, DP | Medium | Low | [LeetCode 918](https://leetcode.com/problems/maximum-sum-circular-subarray/) |
| Stone Game II | Game Theory, Greedy, Array | Medium | Low | [LeetCode 1140](https://leetcode.com/problems/stone-game-ii/) |
| Count Primes | Simulation, Sieve of Eratosthenes | Medium | Medium | [LeetCode 204](https://leetcode.com/problems/count-primes/) |
| House Robber III | DP, Tree Structure | Medium | Low | [LeetCode 337](https://leetcode.com/problems/house-robber-iii/) |
| Convert BST to Greater Tree | Tree, Depth-First Search | Medium | Low | [LeetCode 538](https://leetcode.com/problems/convert-bst-to-greater-tree/) |
| Clone Graph | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 133](https://leetcode.com/problems/clone-graph/) |
| Pacific Atlantic Water Flow | Depth-First Search | Medium | Low | [LeetCode 417](https://leetcode.com/problems/pacific-atlantic-water-flow/) |
| LRU Cache | Design, Hash Table | Medium | High | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Min Stack | Stack, Design | Medium | High | [LeetCode 155](https://leetcode.com/problems/min-stack/) |
| Next Permutation | Array, Two Pointers | Medium | High | [LeetCode 31](https://leetcode.com/problems/next-permutation/) |
| Combination Sum II | Array, Backtracking | Medium | Medium | [LeetCode 40](https://leetcode.com/problems/combination-sum-ii/) |
| Find Bottom Left Tree Value | Tree, Depth-First Search, Breadth-First Search | Medium | Low | [LeetCode 513](https://leetcode.com/problems/find-bottom-left-tree-value/) |
| Maximum Length of Repeated Subarray | Array, Hash Table, String Matching | Medium | Low | [LeetCode 718](https://leetcode.com/problems/maximum-length-of-repeated-subarray/) |
| 3Sum Closest | Array, Two Pointers | Medium | Medium | [LeetCode 16](https://leetcode.com/problems/3sum-closest/) |
| Letter Combinations of a Phone Number | Backtracking, String | Medium | Medium | [LeetCode 17](https://leetcode.com/problems/letter-combinations-of-a-phone-number/) |
| Generate Parentheses | Backtracking | Medium | High | [LeetCode 22](https://leetcode.com/problems/generate-parentheses/) |
| Find First and Last Position of Element in Sorted Array | Array, Binary Search | Medium | Medium | [LeetCode 34](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/) |
| Jump Game II | Array, Greedy | Medium | Medium | [LeetCode 45](https://leetcode.com/problems/jump-game-ii/) |
| Group Anagrams | Array, Hash Table, String | Medium | High | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Merge Intervals | Array, Sorting | Medium | High | [LeetCode 56](https://leetcode.com/problems/merge-intervals/) |
| Subsets | Bit Manipulation, Backtracking | Medium | Medium | [LeetCode 78](https://leetcode.com/problems/subsets/) |
| Binary Tree Level Order Traversal | Tree, Breadth-First Search | Medium | High | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Remove Nth Node From End of List | Linked List, Two Pointers | Medium | Medium | [LeetCode 19](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) |
| Search in Rotated Sorted Array | Array, Binary Search | Medium | Medium | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Reverse Nodes in k-Group | Linked List, Recursion | Medium | Medium | [LeetCode 25](https://leetcode.com/problems/reverse-nodes-in-k-group/) |
| Trapping Rain Water | Stack, Two Pointers | Hard | High | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| Serialize and Deserialize Binary Tree | Tree, Depth-First Search | Hard | Low | [LeetCode 297](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) |
| Count Vowels Permutation | Digit DP, Knapsack | Hard | Low | [LeetCode 1220](https://leetcode.com/problems/count-vowels-permutation/) |
| Sliding Window Maximum | Simulation, Priority Queue | Hard | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Binary Tree Maximum Path Sum | Tree, Depth-First Search | Hard | High | [LeetCode 124](https://leetcode.com/problems/binary-tree-maximum-path-sum/) |
| Word Ladder | Breadth-First Search, String | Hard | Medium | [LeetCode 127](https://leetcode.com/problems/word-ladder/) |
| Word Ladder II | Breadth-First Search, String | Hard | Low | [LeetCode 126](https://leetcode.com/problems/word-ladder-ii/) |
| Profitable Schemes | Array, Dynamic Programming | Hard | Low | [LeetCode 879](https://leetcode.com/problems/profitable-schemes/) |
| Regular Expression Matching | String, Dynamic Programming | Hard | Medium | [LeetCode 10](https://leetcode.com/problems/regular-expression-matching/) |
### Tencent
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Two Sum | Array, Hash Table | Easy | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Linked List Cycle | Linked List, Two Pointers | Easy | High | [LeetCode 141](https://leetcode.com/problems/linked-list-cycle/) |
| Climbing Stairs | Dynamic Programming, Memoization | Easy | High | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Assign Cookies | Greedy, Sorting | Easy | High | [LeetCode 455](https://leetcode.com/problems/assign-cookies/) |
| Best Time to Buy and Sell Stock II | Array, Dynamic Programming | Easy | High | [LeetCode 122](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/) |
| Binary Search | Array, Binary Search | Easy | High | [LeetCode 704](https://leetcode.com/problems/binary-search/) |
| Intersection of Two Linked Lists | Linked List, Two Pointers | Easy | High | [LeetCode 160](https://leetcode.com/problems/intersection-of-two-linked-lists/) |
| Complex Number Multiplication | Math, String | Easy | Medium | [LeetCode 537](https://leetcode.com/problems/complex-number-multiplication/) |
| Number of Islands | Depth-First Search, Breadth-First Search | Medium | High | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Course Schedule | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Coin Change | Dynamic Programming | Medium | High | [LeetCode 322](https://leetcode.com/problems/coin-change/) |
| Unique Paths | Dynamic Programming | Medium | High | [LeetCode 62](https://leetcode.com/problems/unique-paths/) |
| Daily Temperatures | Stack, Monotonic Stack | Medium | High | [LeetCode 739](https://leetcode.com/problems/daily-temperatures/) |
| Generate Parentheses | Backtracking | Medium | High | [LeetCode 22](https://leetcode.com/problems/generate-parentheses/) |
| Letter Combinations of a Phone Number | Backtracking, String | Medium | High | [LeetCode 17](https://leetcode.com/problems/letter-combinations-of-a-phone-number/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Group Anagrams | Array, Hash Table, String | Medium | High | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Merge Intervals | Array, Sorting | Medium | High | [LeetCode 56](https://leetcode.com/problems/merge-intervals/) |
| Task Scheduler | Greedy, Priority Queue | Medium | High | [LeetCode 621](https://leetcode.com/problems/task-scheduler/) |
| Network Delay Time | Graph, Shortest Path | Medium | Medium | [LeetCode 743](https://leetcode.com/problems/network-delay-time/) |
| Cheapest Flights Within K Stops | Graph, Depth-First Search | Medium | Medium | [LeetCode 787](https://leetcode.com/problems/cheapest-flights-within-k-stops/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Longest Increasing Subsequence | Array, Dynamic Programming, Binary Search | Medium | High | [LeetCode 300](https://leetcode.com/problems/longest-increasing-subsequence/) |
| Partition Equal Subset Sum | Dynamic Programming, Knapsack | Medium | Medium | [LeetCode 416](https://leetcode.com/problems/partition-equal-subset-sum/) |
| Word Break | Dynamic Programming, Memoization | Medium | High | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Target Sum | Dynamic Programming, Knapsack | Medium | High | [LeetCode 494](https://leetcode.com/problems/target-sum/) |
| Max Area of Island | Depth-First Search, Breadth-First Search | Medium | High | [LeetCode 695](https://leetcode.com/problems/max-area-of-island/) |
| Container With Most Water | Array, Two Pointers | Medium | High | [LeetCode 11](https://leetcode.com/problems/container-with-most-water/) |
| Valid Sudoku | Array, Hash Table, Backtracking | Medium | High | [LeetCode 36](https://leetcode.com/problems/valid-sudoku/) |
| Number of Recent Calls | Design, Sliding Window | Medium | High | [LeetCode 933](https://leetcode.com/problems/number-of-recent-calls/) |
| Design HashMap | Design, Hash Table | Medium | Medium | [LeetCode 706](https://leetcode.com/problems/design-hashmap/) |
| Design Linked List | Design, Linked List | Medium | High | [LeetCode 707](https://leetcode.com/problems/design-linked-list/) |
| Push Dominoes | Simulation, Queue | Medium | Low | [LeetCode 838](https://leetcode.com/problems/push-dominoes/) |
| Implement Rand10() Using Rand7() | Math, Probability | Medium | High | [LeetCode 470](https://leetcode.com/problems/implement-rand10-using-rand7/) |
| Sliding Window Maximum | Queue, Sliding Window, Heap | Hard | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Trapping Rain Water | Stack, Two Pointers | Hard | High | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| Binary Tree Maximum Path Sum | Tree, Depth-First Search | Hard | High | [LeetCode 124](https://leetcode.com/problems/binary-tree-maximum-path-sum/) |
| Split Array Largest Sum | Binary Search, Dynamic Programming | Hard | Medium | [LeetCode 410](https://leetcode.com/problems/split-array-largest-sum/) |
| Alien Dictionary | Graph, Topological Sort | Hard | Medium | [LeetCode 269](https://leetcode.com/problems/alien-dictionary/) |
| Basic Calculator | Stack, Recursion | Hard | Medium | [LeetCode 224](https://leetcode.com/problems/basic-calculator/) |
| Expression Add Operators | Backtracking, Dynamic Programming | Hard | Medium | [LeetCode 282](https://leetcode.com/problems/expression-add-operators/) |
| Course Schedule III | Greedy, Priority Queue | Hard | Medium | [LeetCode 630](https://leetcode.com/problems/course-schedule-iii/) |
| Maximum Profit in Job Scheduling | Array, Binary Search, Dynamic Programming | Hard | Medium | [LeetCode 1235](https://leetcode.com/problems/maximum-profit-in-job-scheduling/) |
| Strong Password Checker | String, Greedy | Hard | Low | [LeetCode 420](https://leetcode.com/problems/strong-password-checker/) |
| Sliding Puzzle | Breadth-First Search | Hard | Low | [LeetCode 773](https://leetcode.com/problems/sliding-puzzle/) |
| Optimal Account Balancing | Graph, Shortest Path | Hard | Medium | [LeetCode 464](https://leetcode.com/problems/optimal-account-balancing/) |
### Meituan
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Majority Element | Array, Divide and Conquer | Easy | High | [LeetCode 169](https://leetcode.com/problems/majority-element/) |
| Complex Number Multiplication | Math, String | Easy | Medium | [LeetCode 537](https://leetcode.com/problems/complex-number-multiplication/) |
| Path Sum III | Tree, Depth-First Search | Medium | High | [LeetCode 437](https://leetcode.com/problems/path-sum-iii/) |
| Maximum Product Subarray | Array, Dynamic Programming | Medium | High | [LeetCode 152](https://leetcode.com/problems/maximum-product-subarray/) |
| Sort Array By Parity II | Array, Two Pointers | Medium | High | [LeetCode 922](https://leetcode.com/problems/sort-array-by-parity-ii/) |
| Range Sum Query - Mutable | Fenwick Tree, Segment Tree | Medium | High | [LeetCode 307](https://leetcode.com/problems/range-sum-query-mutable/) |
| Implement Rand10() Using Rand7() | Math, Probability | Medium | High | [LeetCode 470](https://leetcode.com/problems/implement-rand10-using-rand7/) |
| Number of Recent Calls | Design, Sliding Window | Medium | High | [LeetCode 933](https://leetcode.com/problems/number-of-recent-calls/) |
| Design HashMap | Design, Hash Table | Medium | High | [LeetCode 706](https://leetcode.com/problems/design-hashmap/) |
| Design Linked List | Design, Linked List | Medium | High | [LeetCode 707](https://leetcode.com/problems/design-linked-list/) |
| Push Dominoes | Simulation, Queue | Medium | Medium | [LeetCode 838](https://leetcode.com/problems/push-dominoes/) |
| Spiral Matrix II | Array, Math | Medium | High | [LeetCode 59](https://leetcode.com/problems/spiral-matrix-ii/) |
| Max Area of Island | Depth-First Search, Breadth-First Search | Medium | Low | [LeetCode 695](https://leetcode.com/problems/max-area-of-island/) |
| Course Schedule II | Graph, Depth-First Search | Medium | Medium | [LeetCode 210](https://leetcode.com/problems/course-schedule-ii/) |
| Partition List | Linked List, Two Pointers | Medium | Low | [LeetCode 86](https://leetcode.com/problems/partition-list/) |
| Decode Ways | Dynamic Programming | Medium | Medium | [LeetCode 91](https://leetcode.com/problems/decode-ways/) |
| Daily Temperatures | Stack, Monotonic Stack | Medium | Medium | [LeetCode 739](https://leetcode.com/problems/daily-temperatures/) |
| Interleaving String | String, Dynamic Programming | Medium | Low | [LeetCode 97](https://leetcode.com/problems/interleaving-string/) |
| Subarray Sum Equals K | Array, Hash Table | Medium | Medium | [LeetCode 560](https://leetcode.com/problems/subarray-sum-equals-k/) |
| Top K Frequent Words | Hash Table, Heap | Medium | Medium | [LeetCode 692](https://leetcode.com/problems/top-k-frequent-words/) |
| 4Sum | Array, Two Pointers | Medium | Low | [LeetCode 18](https://leetcode.com/problems/4sum/) |
| Decode String | Stack, String | Medium | Medium | [LeetCode 394](https://leetcode.com/problems/decode-string/) |
| Zigzag Conversion | String | Medium | Low | [LeetCode 6](https://leetcode.com/problems/zigzag-conversion/) |
| Fizz Buzz Multithreaded | Thread, Design | Medium | Low | [LeetCode 1195](https://leetcode.com/problems/fizz-buzz-multithreaded/) |
| Longest Palindromic Subsequence | String, Dynamic Programming | Medium | Medium | [LeetCode 516](https://leetcode.com/problems/longest-palindromic-subsequence/) |
| Odd Even Linked List | Linked List, Two Pointers | Medium | Low | [LeetCode 328](https://leetcode.com/problems/odd-even-linked-list/) |
| Count of Range Sum | Array, Dynamic Programming | Hard | Low | [LeetCode 327](https://leetcode.com/problems/count-of-range-sum/) |
| Wildcard Matching | String, Dynamic Programming | Hard | Low | [LeetCode 44](https://leetcode.com/problems/wildcard-matching/) |
| Strong Password Checker | String, Greedy | Hard | High | [LeetCode 420](https://leetcode.com/problems/strong-password-checker/) |
| Sliding Puzzle | Breadth-First Search | Hard | Medium | [LeetCode 773](https://leetcode.com/problems/sliding-puzzle/) |
| Optimal Account Balancing | Graph, Shortest Path | Hard | High | [LeetCode 464](https://leetcode.com/problems/optimal-account-balancing/) |
| Burst Balloons | Dynamic Programming, Interval | Hard | High | [LeetCode 312](https://leetcode.com/problems/burst-balloons/) |
| Minimum Window Substring | Hash Table, Sliding Window | Hard | High | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
### Baidu
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Majority Element | Array, Divide and Conquer | Easy | High | [LeetCode 169](https://leetcode.com/problems/majority-element/) |
| Search Insert Position | Array, Binary Search | Easy | High | [LeetCode 35](https://leetcode.com/problems/search-insert-position/) |
| Binary Search | Array, Binary Search | Easy | High | [LeetCode 704](https://leetcode.com/problems/binary-search/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Maximum Subarray | Array, Divide and Conquer, Dynamic Programming | Easy | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Reverse Linked List | Linked List, Recursion | Easy | High | [LeetCode 206](https://leetcode.com/problems/reverse-linked-list/) |
| Merge Two Sorted Lists | Linked List, Recursion | Easy | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Path Sum III | Tree, Depth-First Search | Medium | High | [LeetCode 437](https://leetcode.com/problems/path-sum-iii/) |
| Maximum Product Subarray | Array, Dynamic Programming | Medium | High | [LeetCode 152](https://leetcode.com/problems/maximum-product-subarray/) |
| Sort Array By Parity II | Array, Two Pointers | Medium | Medium | [LeetCode 922](https://leetcode.com/problems/sort-array-by-parity-ii/) |
| Range Sum Query - Mutable | Fenwick Tree, Segment Tree | Medium | High | [LeetCode 307](https://leetcode.com/problems/range-sum-query-mutable/) |
| Implement Rand10() Using Rand7() | Math, Probability | Medium | High | [LeetCode 470](https://leetcode.com/problems/implement-rand10-using-rand7/) |
| Number of Recent Calls | Design, Sliding Window | Medium | High | [LeetCode 933](https://leetcode.com/problems/number-of-recent-calls/) |
| Design HashMap | Design, Hash Table | Medium | High | [LeetCode 706](https://leetcode.com/problems/design-hashmap/) |
| Design Linked List | Design, Linked List | Medium | High | [LeetCode 707](https://leetcode.com/problems/design-linked-list/) |
| Push Dominoes | Simulation, Queue | Medium | Medium | [LeetCode 838](https://leetcode.com/problems/push-dominoes/) |
| Search in Rotated Sorted Array | Array, Binary Search | Medium | High | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Find Minimum in Rotated Sorted Array | Array, Binary Search | Medium | High | [LeetCode 153](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/) |
| Search a 2D Matrix | Array, Binary Search | Medium | High | [LeetCode 74](https://leetcode.com/problems/search-a-2d-matrix/) |
| Longest Substring Without Repeating Characters | Hash Table, String, Sliding Window | Medium | High | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Longest Increasing Subsequence | Array, Dynamic Programming, Binary Search | Medium | High | [LeetCode 300](https://leetcode.com/problems/longest-increasing-subsequence/) |
| String to Integer | String, Simulation | Medium | High | [LeetCode 8](https://leetcode.com/problems/string-to-integer-atoi/) |
| Add Strings | String, Math | Medium | High | [LeetCode 415](https://leetcode.com/problems/add-strings/) |
| LRU Cache | Hash Table, Doubly Linked List, Design | Medium | High | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Jump Game | Greedy | Medium | Medium | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Combination Sum II | Backtracking | Medium | Low | [LeetCode 40](https://leetcode.com/problems/combination-sum-ii/) |
| Number of Longest Increasing Subsequence | Dynamic Programming | Medium | Medium | [LeetCode 673](https://leetcode.com/problems/number-of-longest-increasing-subsequence/) |
| Spiral Matrix | Array | Medium | Low | [LeetCode 54](https://leetcode.com/problems/spiral-matrix/) |
| Container With Most Water | Array, Two Pointers | Medium | Medium | [LeetCode 11](https://leetcode.com/problems/container-with-most-water/) |
| Find the Duplicate Number | Linked List, Binary Search | Medium | Low | [LeetCode 287](https://leetcode.com/problems/find-the-duplicate-number/) |
| Largest Number | Sorting | Medium | Medium | [LeetCode 179](https://leetcode.com/problems/largest-number/) |
| Compare Version Numbers | Two Pointers | Medium | Low | [LeetCode 165](https://leetcode.com/problems/compare-version-numbers/) |
| Remove Duplicates from Sorted List II | Linked List | Medium | Medium | [LeetCode 82](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii/) |
| Next Permutation | Array | Medium | Low | [LeetCode 31](https://leetcode.com/problems/next-permutation/) |
| Monotone Increasing Digits | Greedy | Medium | Medium | [LeetCode 738](https://leetcode.com/problems/monotone-increasing-digits/) |
| House Robber II | Dynamic Programming | Medium | Low | [LeetCode 213](https://leetcode.com/problems/house-robber-ii/) |
| Minimum Window Substring | Hash Table, Sliding Window | Hard | High | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
| Median of Two Sorted Arrays | Array, Binary Search | Hard | High | [LeetCode 4](https://leetcode.com/problems/median-of-two-sorted-arrays/) |
| Regular Expression Matching | String, Dynamic Programming | Hard | High | [LeetCode 10](https://leetcode.com/problems/regular-expression-matching/) |
| Wildcard Matching | String, Dynamic Programming | Hard | High | [LeetCode 44](https://leetcode.com/problems/wildcard-matching/) |
| Edit Distance | Dynamic Programming | Hard | High | [LeetCode 72](https://leetcode.com/problems/edit-distance/) |
| Burst Balloons | Dynamic Programming, Interval | Hard | High | [LeetCode 312](https://leetcode.com/problems/burst-balloons/) |
| Best Time to Buy and Sell Stock with Cooldown | Array, Dynamic Programming | Hard | High | [LeetCode 309](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/) |
| Best Time to Buy and Sell Stock IV | Array, Dynamic Programming | Hard | High | [LeetCode 188](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv/) |
| Serialize and Deserialize Binary Tree | Tree, Depth-First Search | Hard | High | [LeetCode 297](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) |
| Expression Add Operators | Backtracking, Dynamic Programming | Hard | High | [LeetCode 282](https://leetcode.com/problems/expression-add-operators/) |
| Basic Calculator | Stack, Recursion | Hard | High | [LeetCode 224](https://leetcode.com/problems/basic-calculator/) |
| Alien Dictionary | Graph, Topological Sort | Hard | High | [LeetCode 269](https://leetcode.com/problems/alien-dictionary/) |
| Course Schedule III | Greedy, Priority Queue | Hard | High | [LeetCode 630](https://leetcode.com/problems/course-schedule-iii/) |
| Maximum Profit in Job Scheduling | Array, Binary Search, Dynamic Programming | Hard | High | [LeetCode 1235](https://leetcode.com/problems/maximum-profit-in-job-scheduling/) |
| Sequence Reconstruction | Graph, Topological Sort | Hard | Medium | [LeetCode 444](https://leetcode.com/problems/sequence-reconstruction/) |
| Sell Diminishing-Valued Colored Balls | Greedy, Priority Queue | Hard | Medium | [LeetCode 1648](https://leetcode.com/problems/sell-diminishing-valued-colored-balls/) |
| Strong Password Checker | String, Greedy | Hard | Medium | [LeetCode 420](https://leetcode.com/problems/strong-password-checker/) |
| Sliding Puzzle | Breadth-First Search | Hard | Medium | [LeetCode 773](https://leetcode.com/problems/sliding-puzzle/) |
| Optimal Account Balancing | Graph, Shortest Path | Hard | Medium | [LeetCode 464](https://leetcode.com/problems/optimal-account-balancing/) |
| Reverse Nodes in k-Group | Linked List, Recursion | Hard | High | [LeetCode 25](https://leetcode.com/problems/reverse-nodes-in-k-group/) |
| Longest Valid Parentheses | String, Stack, Dynamic Programming | Hard | Medium | [LeetCode 32](https://leetcode.com/problems/longest-valid-parentheses/) |
### JD.com
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Majority Element | Array, Divide and Conquer | Easy | High | [LeetCode 169](https://leetcode.com/problems/majority-element/) |
| Search Insert Position | Array, Binary Search | Easy | High | [LeetCode 35](https://leetcode.com/problems/search-insert-position/) |
| Fibonacci Number | Dynamic Programming | Easy | Medium | [LeetCode 509](https://leetcode.com/problems/fibonacci-number/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Linked List, Recursion | Easy | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Path Sum III | Tree, Depth-First Search | Medium | Medium | [LeetCode 437](https://leetcode.com/problems/path-sum-iii/) |
| Maximum Product Subarray | Array, Dynamic Programming | Medium | Medium | [LeetCode 152](https://leetcode.com/problems/maximum-product-subarray/) |
| Sort Array By Parity II | Array, Two Pointers | Medium | Medium | [LeetCode 922](https://leetcode.com/problems/sort-array-by-parity-ii/) |
| Range Sum Query - Mutable | Fenwick Tree, Segment Tree | Medium | Medium | [LeetCode 307](https://leetcode.com/problems/range-sum-query-mutable/) |
| Implement Rand10() Using Rand7() | Math, Probability | Medium | Medium | [LeetCode 470](https://leetcode.com/problems/implement-rand10-using-rand7/) |
| Number of Recent Calls | Design, Sliding Window | Medium | Medium | [LeetCode 933](https://leetcode.com/problems/number-of-recent-calls/) |
| Design HashMap | Design, Hash Table | Medium | High | [LeetCode 706](https://leetcode.com/problems/design-hashmap/) |
| Design Linked List | Design, Linked List | Medium | High | [LeetCode 707](https://leetcode.com/problems/design-linked-list/) |
| Push Dominoes | Simulation, Queue | Medium | Medium | [LeetCode 838](https://leetcode.com/problems/push-dominoes/) |
| Search in Rotated Sorted Array | Array, Binary Search | Medium | High | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Find Minimum in Rotated Sorted Array | Array, Binary Search | Medium | High | [LeetCode 153](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/) |
| Longest Substring Without Repeating Characters | Hash Table, String, Sliding Window | Medium | High | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Permutations | Array, Backtracking | Medium | High | [LeetCode 46](https://leetcode.com/problems/permutations/) |
| Linked List Cycle II | Linked List, Two Pointers | Medium | High | [LeetCode 142](https://leetcode.com/problems/linked-list-cycle-ii/) |
| Sort an Array | Array, Sorting | Medium | High | [LeetCode 912](https://leetcode.com/problems/sort-an-array/) |
| LRU Cache | Hash Table, Doubly Linked List, Design | Medium | High | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Complex Number Multiplication | Math, String | Medium | Medium | [LeetCode 537](https://leetcode.com/problems/complex-number-multiplication/) |
| Combinations | Backtracking | Medium | Low | [LeetCode 77](https://leetcode.com/problems/combinations/) |
| Find First and Last Position of Element in Sorted Array | Array, Binary Search | Medium | Low | [LeetCode 34](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/) |
| Subarray Sum Equals K | Array, Hash Table | Medium | Low | [LeetCode 560](https://leetcode.com/problems/subarray-sum-equals-k/) |
| Evaluate Reverse Polish Notation | Stack | Medium | Low | [LeetCode 150](https://leetcode.com/problems/evaluate-reverse-polish-notation/) |
| Binary Tree Right Side View | Tree, Breadth-First Search | Medium | Low | [LeetCode 199](https://leetcode.com/problems/binary-tree-right-side-view/) |
| Max Area of Island | Depth-First Search, Breadth-First Search | Medium | Low | [LeetCode 695](https://leetcode.com/problems/max-area-of-island/) |
| Binary Tree Level Order Traversal II | Tree, Breadth-First Search | Medium | Low | [LeetCode 107](https://leetcode.com/problems/binary-tree-level-order-traversal-ii/) |
| Minimum Window Substring | Hash Table, Sliding Window | Hard | Medium | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
| Burst Balloons | Dynamic Programming, Interval | Hard | Medium | [LeetCode 312](https://leetcode.com/problems/burst-balloons/) |
| Optimal Account Balancing | Graph, Shortest Path | Hard | Medium | [LeetCode 464](https://leetcode.com/problems/optimal-account-balancing/) |
| Strong Password Checker | String, Greedy | Hard | Medium | [LeetCode 420](https://leetcode.com/problems/strong-password-checker/) |
| Sliding Puzzle | Breadth-First Search | Hard | Medium | [LeetCode 773](https://leetcode.com/problems/sliding-puzzle/) |
| Sliding Window Maximum | Queue, Sliding Window, Heap | Hard | Low | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Candy | Greedy | Hard | Low | [LeetCode 135](https://leetcode.com/problems/candy/) |
| First Missing Positive | Array | Hard | Low | [LeetCode 41](https://leetcode.com/problems/first-missing-positive/) |
### Huawei
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Number of 1 Bits | Bit Manipulation | Easy | High | [LeetCode 191](https://leetcode.com/problems/number-of-1-bits/) |
| Maximum Depth of Binary Tree | Tree, Depth-First Search | Easy | Medium | [LeetCode 104](https://leetcode.com/problems/maximum-depth-of-binary-tree/) |
| Invert Binary Tree | Tree, Depth-First Search | Easy | Low | [LeetCode 226](https://leetcode.com/problems/invert-binary-tree/) |
| Path Sum | Tree, Depth-First Search | Easy | Low | [LeetCode 112](https://leetcode.com/problems/path-sum/) |
| Reverse Integer | Math | Easy | Medium | [LeetCode 7](https://leetcode.com/problems/reverse-integer/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Longest Continuous Increasing Subsequence | Array, Dynamic Programming | Medium | Low | [LeetCode 674](https://leetcode.com/problems/longest-continuous-increasing-subsequence/) |
| Longest Increasing Subsequence | Array, Dynamic Programming, Binary Search | Medium | High | [LeetCode 300](https://leetcode.com/problems/longest-increasing-subsequence/) |
| Implement Trie (Prefix Tree) | Design, Data Structure | Medium | Medium | [LeetCode 208](https://leetcode.com/problems/implement-trie-prefix-tree/) |
| Contains Duplicate III | Array, Sliding Window | Medium | Low | [LeetCode 220](https://leetcode.com/problems/contains-duplicate-iii/) |
| Flatten Binary Tree to Linked List | Tree, Depth-First Search | Medium | Low | [LeetCode 114](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/) |
| Symmetric Tree | Tree, Recursion | Medium | Medium | [LeetCode 101](https://leetcode.com/problems/symmetric-tree/) |
| Binary Tree Level Order Traversal | Tree, Breadth-First Search | Medium | Medium | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Lowest Common Ancestor of a Binary Tree | Tree, Depth-First Search | Medium | Medium | [LeetCode 236](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/) |
| Min Stack | Stack, Design | Medium | High | [LeetCode 155](https://leetcode.com/problems/min-stack/) |
| Sliding Window Maximum | Queue, Sliding Window | Medium | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Longest Substring Without Repeating Characters | Hash Table, String, Sliding Window | Medium | High | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Daily Temperatures | Stack, Monotonic Stack | Medium | Medium | [LeetCode 739](https://leetcode.com/problems/daily-temperatures/) |
| Brick Wall | Array, Hash Table | Medium | Low | [LeetCode 554](https://leetcode.com/problems/brick-wall/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Permutations | Array, Backtracking | Medium | Medium | [LeetCode 46](https://leetcode.com/problems/permutations/) |
| Number of Islands | Depth-First Search, Breadth-First Search | Medium | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Merge Intervals | Array, Sorting | Medium | Medium | [LeetCode 56](https://leetcode.com/problems/merge-intervals/) |
| Coin Change | Dynamic Programming | Medium | Medium | [LeetCode 322](https://leetcode.com/problems/coin-change/) |
| Longest Palindromic Substring | String, Dynamic Programming | Medium | High | [LeetCode 5](https://leetcode.com/problems/longest-palindromic-substring/) |
| Remove Duplicate Letters | String, Monotonic Stack | Medium | Low | [LeetCode 316](https://leetcode.com/problems/remove-duplicate-letters/) |
| Basic Calculator II | Stack, Math | Medium | Low | [LeetCode 227](https://leetcode.com/problems/basic-calculator-ii/) |
| Decode String | Stack, String | Medium | Medium | [LeetCode 394](https://leetcode.com/problems/decode-string/) |
| Restore IP Addresses | String, Backtracking | Medium | Low | [LeetCode 93](https://leetcode.com/problems/restore-ip-addresses/) |
| Reverse Nodes in k-Group | Linked List, Recursion | Hard | Medium | [LeetCode 25](https://leetcode.com/problems/reverse-nodes-in-k-group/) |
| Merge k Sorted Lists | Linked List, Heap, Divide and Conquer | Hard | Medium | [LeetCode 23](https://leetcode.com/problems/merge-k-sorted-lists/) |
| Regular Expression Matching | String, Dynamic Programming | Hard | Low | [LeetCode 10](https://leetcode.com/problems/regular-expression-matching/) |
| Minimum Window Substring | Hash Table, Sliding Window | Hard | Low | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
| Median of Two Sorted Arrays | Array, Binary Search | Hard | Medium | [LeetCode 4](https://leetcode.com/problems/median-of-two-sorted-arrays/) |
| Largest Rectangle in Histogram | Stack, Array, Monotonic Stack | Hard | Low | [LeetCode 84](https://leetcode.com/problems/largest-rectangle-in-histogram/) |
| Edit Distance | String, Dynamic Programming | Hard | Medium | [LeetCode 72](https://leetcode.com/problems/edit-distance/) |
| Word Ladder | Graph, Breadth-First Search | Hard | Low | [LeetCode 127](https://leetcode.com/problems/word-ladder/) |
| The Skyline Problem | Fenwick Tree, Segment Tree, Sweep Line | Hard | Low | [LeetCode 218](https://leetcode.com/problems/the-skyline-problem/) |
| Burst Balloons | Dynamic Programming, Interval | Hard | Low | [LeetCode 312](https://leetcode.com/problems/burst-balloons/) |
| Optimal Account Balancing | Graph, Dynamic Programming, State Compression | Hard | Low | [LeetCode 464](https://leetcode.com/problems/optimal-account-balancing/) |
### Xiaomi
| Problem Name | Tags | Difficulty | Frequency | Problem Link |
|--------------|------|------------|-----------|--------------|
| Kth Largest Element in a Stream | Heap, Design | Easy | High | [LeetCode 703](https://leetcode.com/problems/kth-largest-element-in-a-stream/) |
| Valid Parentheses | Stack, String | Easy | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Reverse Linked List | Linked List, Recursion | Easy | High | [LeetCode 206](https://leetcode.com/problems/reverse-linked-list/) |
| Merge Two Sorted Lists | Linked List, Recursion | Easy | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Maximum Subarray | Array, Divide and Conquer, Dynamic Programming | Easy | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Merge Sorted Array | Array, Two Pointers | Easy | High | [LeetCode 88](https://leetcode.com/problems/merge-sorted-array/) |
| Add Two Numbers | Linked List, Math | Medium | High | [LeetCode 2](https://leetcode.com/problems/add-two-numbers/) |
| Sort Colors | Array, Two Pointers, Sorting | Medium | High | [LeetCode 75](https://leetcode.com/problems/sort-colors/) |
| Decode String | Stack, String | Medium | High | [LeetCode 394](https://leetcode.com/problems/decode-string/) |
| Number of Islands | Depth-First Search, Breadth-First Search, Union Find | Medium | High | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Longest Palindromic Substring | String, Dynamic Programming | Medium | High | [LeetCode 5](https://leetcode.com/problems/longest-palindromic-substring/) |
| Longest Substring Without Repeating Characters | Hash Table, String, Sliding Window | Medium | High | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Binary Tree Level Order Traversal | Tree, Breadth-First Search | Medium | High | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Kth Largest Element in an Array | Array, Heap, Divide and Conquer | Medium | High | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Reorder List | Linked List, Stack | Medium | Medium | [LeetCode 143](https://leetcode.com/problems/reorder-list/) |
| 3Sum | Array, Two Pointers | Medium | High | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Implement Queue using Stacks | Stack, Design | Medium | Medium | [LeetCode 232](https://leetcode.com/problems/implement-queue-using-stacks/) |
| Implement Stack using Queues | Design, Queue | Medium | Medium | [LeetCode 225](https://leetcode.com/problems/implement-stack-using-queues/) |
| Remove Nth Node From End of List | Linked List, Two Pointers | Medium | High | [LeetCode 19](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) |
| Search in Rotated Sorted Array | Array, Binary Search | Medium | Medium | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Longest Common Subsequence | Array, Dynamic Programming | Medium | Medium | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Edit Distance | String, Dynamic Programming | Hard | Medium | [LeetCode 72](https://leetcode.com/problems/edit-distance/) |
| Longest Valid Parentheses | String, Stack, Dynamic Programming | Hard | Medium | [LeetCode 32](https://leetcode.com/problems/longest-valid-parentheses/) |
| Find Median from Data Stream | Design, Heap | Hard | Medium | [LeetCode 295](https://leetcode.com/problems/find-median-from-data-stream/) |
| Median of Two Sorted Arrays | Array, Binary Search | Hard | Medium | [LeetCode 4](https://leetcode.com/problems/median-of-two-sorted-arrays/) |
| Largest Rectangle in Histogram | Stack, Array | Hard | Medium | [LeetCode 84](https://leetcode.com/problems/largest-rectangle-in-histogram/) |
| The Skyline Problem | Fenwick Tree, Segment Tree, Sweep Line | Hard | Low | [LeetCode 218](https://leetcode.com/problems/the-skyline-problem/) |
| Maximal Rectangle | Stack, Array, Dynamic Programming | Hard | Low | [LeetCode 85](https://leetcode.com/problems/maximal-rectangle/) |
### Microsoft
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Product of Array Except Self | Medium | Array, Prefix Sum | Medium | [LeetCode 238](https://leetcode.com/problems/product-of-array-except-self/) |
| Container With Most Water | Medium | Array, Two Pointers | Medium | [LeetCode 11](https://leetcode.com/problems/container-with-most-water/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| Rotate Array | Medium | Array, Math | Low | [LeetCode 189](https://leetcode.com/problems/rotate-array/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Low | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Course Schedule | Medium | Graph, Depth-First Search | Low | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Low | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Longest Palindromic Substring | Medium | String, Dynamic Programming | Low | [LeetCode 5](https://leetcode.com/problems/longest-palindromic-substring/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
| Permutations | Medium | Backtracking, Array | Low | [LeetCode 46](https://leetcode.com/problems/permutations/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Serialize and Deserialize Binary Tree | Hard | Tree, String | Low | [LeetCode 297](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) |
### Didi
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Design HashMap | Easy | Hash Table, Design | Medium | [LeetCode 706](https://leetcode.com/problems/design-hashmap/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| 3Sum | Medium | Array, Two Pointers | Medium | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Remove Nth Node From End of List | Medium | Linked List, Two Pointers | Medium | [LeetCode 19](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Sliding Window Maximum | Medium | Array, Sliding Window | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Reservoir Sampling | Medium | Math, Rejection Sampling | Low | [LeetCode 382](https://leetcode.com/problems/linked-list-random-node/) |
| Serialize and Deserialize Binary Tree | Hard | Tree, String | Low | [LeetCode 297](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/) |
### Ctrip
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Intersection of Two Linked Lists | Easy | Linked List, Two Pointers | Low | [LeetCode 160](https://leetcode.com/problems/intersection-of-two-linked-lists/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Sliding Window Maximum | Medium | Array, Sliding Window | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Cheapest Flights Within K Stops | Medium | Graph, Dynamic Programming | Medium | [LeetCode 787](https://leetcode.com/problems/cheapest-flights-within-k-stops/) |
| Next Permutation | Medium | Array, Two Pointers | Low | [LeetCode 31](https://leetcode.com/problems/next-permutation/) |
| Reconstruct Itinerary | Hard | Graph, Depth-First Search | Medium | [LeetCode 332](https://leetcode.com/problems/reconstruct-itinerary/) |
| Bus Routes | Breadth-First Search, Array | Medium | Low | [LeetCode 815](https://leetcode.com/problems/bus-routes/) |
| 3Sum | Medium | Array, Two Pointers | Low | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Remove Nth Node From End of List | Medium | Linked List, Two Pointers | Low | [LeetCode 19](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
### Pinduoduo
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Majority Element | Easy | Array, Bit Manipulation | Low | [LeetCode 169](https://leetcode.com/problems/majority-element/) |
| Trapping Rain Water | Hard | Array, Two Pointers | High | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| Minimum Window Substring | Hard | Hash Table, Sliding Window | High | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Sliding Window Maximum | Medium | Array, Sliding Window | High | [LeetCode 239](https://leetcode.com/problems/sliding-window-maximum/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| 3Sum | Medium | Array, Two Pointers | Low | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| House Robber | Medium | Dynamic Programming, Array | Low | [LeetCode 198](https://leetcode.com/problems/house-robber/) |
| Partition Equal Subset Sum | Medium | Dynamic Programming, Array | Low | [LeetCode 416](https://leetcode.com/problems/partition-equal-subset-sum/) |
| Construct Binary Tree from Preorder and Inorder Traversal | Medium | Tree, Depth-First Search | Low | [LeetCode 105](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/) |
| Reorder List | Medium | Linked List, Two Pointers | Low | [LeetCode 143](https://leetcode.com/problems/reorder-list/) |
| Sort List | Medium | Linked List, Two Pointers | Low | [LeetCode 148](https://leetcode.com/problems/sort-list/) |
| Binary Tree Level Order Traversal | Medium | Tree, Breadth-First Search | Low | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Compare Version Numbers | Medium | String, Two Pointers | Low | [LeetCode 165](https://leetcode.com/problems/compare-version-numbers/) |
| Min Stack | Medium | Stack, Design | Low | [LeetCode 155](https://leetcode.com/problems/min-stack/) |
| Largest Rectangle in Histogram | Hard | Array, Stack | Low | [LeetCode 84](https://leetcode.com/problems/largest-rectangle-in-histogram/) |
| Merge k Sorted Lists | Hard | Linked List, Heap | Low | [LeetCode 23](https://leetcode.com/problems/merge-k-sorted-lists/) |
| Find Median from Data Stream | Hard | Array, Binary Search | Low | [LeetCode 295](https://leetcode.com/problems/find-median-from-data-stream/) |
| Sliding Window Median | Hard | Heap, Design | Low | [LeetCode 295](https://leetcode.com/problems/sliding-window-median/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
### Xiaohongshu
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Sum Root to Leaf Numbers | Medium | Tree, Depth-First Search | Medium | [LeetCode 129](https://leetcode.com/problems/sum-root-to-leaf-numbers/) |
| Surrounded Regions | Medium | Depth-First Search, Breadth-First Search | Low | [LeetCode 130](https://leetcode.com/problems/surrounded-regions/) |
| Binary Tree Level Order Traversal | Medium | Tree, Breadth-First Search | Low | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Longest Increasing Subsequence | Medium | Dynamic Programming, Array | High | [LeetCode 300](https://leetcode.com/problems/longest-increasing-subsequence/) |
| Interleaving String | Medium | Dynamic Programming, String | Medium | [LeetCode 97](https://leetcode.com/problems/interleaving-string/) |
| Trapping Rain Water | Hard | Array, Two Pointers | High | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| Longest Palindromic Substring | Medium | String, Dynamic Programming | Low | [LeetCode 5](https://leetcode.com/problems/longest-palindromic-substring/) |
| 3Sum | Medium | Array, Two Pointers | Low | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
### vivo
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Binary Tree Level Order Traversal | Medium | Tree, Breadth-First Search | High | [LeetCode 102](https://leetcode.com/problems/binary-tree-level-order-traversal/) |
| Path Sum | Easy | Tree, Depth-First Search | Medium | [LeetCode 112](https://leetcode.com/problems/path-sum/) |
| Invert Binary Tree | Easy | Tree, Recursion | Low | [LeetCode 226](https://leetcode.com/problems/invert-binary-tree/) |
| Android Unlock Patterns | Medium | Depth-First Search, Backtracking | Low | [LeetCode 351](https://leetcode.com/problems/android-unlock-patterns/) |
| Trapping Rain Water | Hard | Array, Two Pointers | Low | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| 3Sum | Medium | Array, Two Pointers | Low | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
### OPPO
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Reverse Linked List | Easy | Linked List, Recursion | Medium | [LeetCode 206](https://leetcode.com/problems/reverse-linked-list/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Container With Most Water | Medium | Array, Two Pointers | Medium | [LeetCode 11](https://leetcode.com/problems/container-with-most-water/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Minimum Window Substring | Hard | Hash Table, Sliding Window | Low | [LeetCode 76](https://leetcode.com/problems/minimum-window-substring/) |
| Longest Valid Parentheses | Medium | Stack, String | Low | [LeetCode 32](https://leetcode.com/problems/longest-valid-parentheses/) |
| Substring with Concatenation of All Words | Medium | Hash Table, Sliding Window | Low | [LeetCode 30](https://leetcode.com/problems/substring-with-concatenation-of-all-words/) |
| Binary Tree Maximum Path Sum | Hard | Tree, Depth-First Search | Low | [LeetCode 124](https://leetcode.com/problems/binary-tree-maximum-path-sum/) |
| Trapping Rain Water | Hard | Array, Two Pointers | Low | [LeetCode 42](https://leetcode.com/problems/trapping-rain-water/) |
| 3Sum | Medium | Array, Two Pointers | Low | [LeetCode 15](https://leetcode.com/problems/3sum/) |
| Group Anagrams | Medium | String, Hash Table | Low | [LeetCode 49](https://leetcode.com/problems/group-anagrams/) |
| Search in Rotated Sorted Array | Medium | Binary Search, Array | Low | [LeetCode 33](https://leetcode.com/problems/search-in-rotated-sorted-array/) |
| Jump Game | Medium | Greedy, Array | Low | [LeetCode 55](https://leetcode.com/problems/jump-game/) |
| Word Break | Medium | Dynamic Programming, String | Low | [LeetCode 139](https://leetcode.com/problems/word-break/) |
| Longest Common Subsequence | Medium | Dynamic Programming, String | Low | [LeetCode 1143](https://leetcode.com/problems/longest-common-subsequence/) |
| Combination Sum | Medium | Backtracking, Array | Low | [LeetCode 39](https://leetcode.com/problems/combination-sum/) |
### Ant Group
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| House Robber | Medium | Dynamic Programming, Array | High | [LeetCode 198](https://leetcode.com/problems/house-robber/) |
| Partition Equal Subset Sum | Medium | Dynamic Programming, Array | Medium | [LeetCode 416](https://leetcode.com/problems/partition-equal-subset-sum/) |
| Task Scheduler | Medium | Greedy, Array | Medium | [LeetCode 621](https://leetcode.com/problems/task-scheduler/) |
### iFlytek
| Problem Name | Difficulty | Tags | Frequency | Problem Link |
|--------------|------------|------|-----------|--------------|
| Two Sum | Easy | Array, Hash Table | High | [LeetCode 1](https://leetcode.com/problems/two-sum/) |
| Valid Parentheses | Easy | Stack, String | High | [LeetCode 20](https://leetcode.com/problems/valid-parentheses/) |
| Merge Two Sorted Lists | Easy | Linked List, Recursion | High | [LeetCode 21](https://leetcode.com/problems/merge-two-sorted-lists/) |
| Climbing Stairs | Easy | Dynamic Programming, Array | Medium | [LeetCode 70](https://leetcode.com/problems/climbing-stairs/) |
| Valid Palindrome | Easy | String, Two Pointers | Medium | [LeetCode 125](https://leetcode.com/problems/valid-palindrome/) |
| Maximum Subarray | Medium | Array, Dynamic Programming | High | [LeetCode 53](https://leetcode.com/problems/maximum-subarray/) |
| Best Time to Buy and Sell Stock | Medium | Array, Dynamic Programming | High | [LeetCode 121](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/) |
| Longest Substring Without Repeating Characters | Medium | String, Sliding Window | Medium | [LeetCode 3](https://leetcode.com/problems/longest-substring-without-repeating-characters/) |
| Kth Largest Element in an Array | Medium | Array, Heap | Medium | [LeetCode 215](https://leetcode.com/problems/kth-largest-element-in-an-array/) |
| LRU Cache | Medium | Hash Table, Doubly Linked List | Medium | [LeetCode 146](https://leetcode.com/problems/lru-cache/) |
| Course Schedule | Medium | Graph, Depth-First Search | Medium | [LeetCode 207](https://leetcode.com/problems/course-schedule/) |
| Number of Islands | Medium | Depth-First Search, Breadth-First Search | Medium | [LeetCode 200](https://leetcode.com/problems/number-of-islands/) |
| Minimum Path Sum | Medium | Dynamic Programming, Matrix | Medium | [LeetCode 64](https://leetcode.com/problems/minimum-path-sum/) |
| Longest Increasing Subsequence | Medium | Dynamic Programming, Array | High | [LeetCode 300](https://leetcode.com/problems/longest-increasing-subsequence/) |
| Interleaving String | Medium | Dynamic Programming, String | Medium | [LeetCode 97](https://leetcode.com/problems/interleaving-string/) |
| Edit Distance | Medium | Dynamic Programming, String | Medium | [LeetCode 72](https://leetcode.com/problems/edit-distance/) |
## 🌐 Practice Platforms
- [LeetCode](https://leetcode.com/)
- [NowCoder](https://www.nowcoder.com/)
- [AcWing](https://www.acwing.com/problem/)
## 🔗 Resource Notes
The questions in this repository are sourced from reliable channels:
- **LeetCode**: Core problem bank and original links.
- **NowCoder**: Big tech written test/interview recaps and variants.
- **CodeTop**: High-frequency question statistics.
**Disclaimer**:
- All questions and related content in this repository are for learning and exchange only. When practicing, combine with official solutions to verify ideas.
- During resource compilation, there may be broken links or information errors. If you find issues, welcome to leave feedback in Issues. Thank you for your corrections and support!
## 🚀 Contribution Guidelines
Thank you for supporting Awesome-BigTech-Algorithms! We welcome all contributions, including reporting errors, adding new questions, and fixing dead links. Your feedback makes the resources richer and more accurate, helping more people prepare for big tech interviews.
### How to Contribute
1. **Report Issues**: Open a new [Issue](https://github.com/0voice/Awesome-BigTech-Algorithms/issues). Describe the problem (e.g., "ByteDance table LC 20 link broken"), and we'll fix it promptly.
2. **Submit Pull Request (PR)**:
- Fork the repository, create a branch (e.g., `fix/byte-link`).
- Update table format: Keep consistent (Problem Name | Tags | Difficulty | Frequency | LeetCode Link).
- New questions suggestion: Prioritize high-frequency/2025 new points, with source.
- Commit message: Concise description (e.g., "Update: Fix Alibaba LC 15 link").
- Push to your Fork, create PR linking the related Issue.