> For the complete documentation index, see [llms.txt](https://zhangjelly0405.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zhangjelly0405.gitbook.io/leetcode/master.md).
# README
## Leetcode Summary
Author: Jelly.
If this repo helps you, please give it a 🌟. Thanks.
Gitbook link:
Github link:
## Important Questions
| # | Title | Importance |
| ----------------- | ---------------------------------------------- | ---------- |
| **Array** | | |
| 4 | Median of Two Sorted Arrays | ★★★★★ |
| 11 | Container With Most Water | ★★★ |
| 15 | 3Sum | ★★★★★ |
| 81 | Search in Rotated Sorted Array II | ★★★★★ |
| 41 | First Missing Positive | ★★★★★ |
| 42 | Trapping Rain Water | ★★★★★ |
| 56 | Merge Intervals | ★★★★★ |
| 60 | Permutation Sequence | ★★★ |
| 154 | Find Minimum in Rotated Sorted Array II | ★★★★ |
| 215 | Kth Largest Element in an Array | ★★★★★ |
| 315 | Count of Smaller Numbers After Self | ★★★ |
| 188 | Best Time to Buy and Sell Stock IV | ★★★★★ |
| 862 | Shortest Subarray with Sum at Least K | ★★★★★ |
| 51 | Maximum Subarray | ★★★★★ |
| 300 | Longest Increasing Subsequence | ★★★★★ |
| 43 | Multiply Strings | ★★★★ |
| | | |
| **String** | | |
| 3 | Longest Substring Without Repeating Characters | ★★★ |
| 5 | Longest Palindromic Substring | ★★★ |
| 8 | String to Integer (atoi) | ★★★★ |
| 28 | Implement strStr() | ★★★★★ |
| 32 | Longest Valid Parentheses | |
| | | |
| | | |
| **LinkList** | | |
| 2 | Add Two Numbers | ★★★ |
| 23 | Merge k Sorted Lists | ★★★ |
| 25 | Reverse Nodes in k-Group | ★★★★★ |
| 142 | Linked List Cycle II | ★★★ |
| 143 | Reorder List | ★★★★ |
| | | |
| | | |
| **Tree** | | |
| 230 | Kth Smallest Element in a BST | ★★ |
| 98 | Validate Binary Search Tree | ★★★ |
| 102 | Binary Tree Level Order Traversal | ★★★ |
| 94 | Binary Tree Inorder Traversal | ★★★★★ |
| 144 | Binary Tree Preorder Traversal | ★★★★★ |
| 145 | Binary Tree Postorder Traversal | ★★★★★ |
| 236 | Lowest Common Ancestor of a Binary Tree | ★★★ |
| | | |
| | | |
| **DP** | | |
| 10 | Regular Expression Matching | ★★★★ |
| 44 | Wildcard Matching | ★★★★ |
| 72 | Edit Distance | ★★★★ |
| 132 | Palindrome Partitioning II | ★★★ |
| 338 | Counting Bits | ★★★ |
| 877 | Stone Game | ★★★★ |
| 1043 | Partition Array for Maximum Sum | ★★★ |
| 1406 | Stone Game III | ★★★★ |
| 416 | Partition Equal Subset Sum | ★★★★ |
| | | |
| | | |
| **DFS/BFS** | | |
| 40 | Combination Sum II | ★★★ |
| 31 | Next Permutation | ★★★★★ |
| 47 | Permutations II | ★★★★ |
| 131 | Palindrome Partitioning | ★★ |
| | | |
| | | |
| **Bit Operation** | | |
| 371 | Sum of Two Integers | ★★ |
| | | |
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| | | |
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| **Others** | | |
| 29 | Divide Two Integers | ★★★ |
| 50 | Pow(x, n) | ★★★ |
| 69 | Sqrt(x) | ★★★ |
| 133 | Clone Graph | ★★★ |
| 969 | Pancake Sorting | ★★★ |
| 224 | Basic Calculator | ★★★★ |
| 547 | Friend Circles | ★★★★ |
| 146 | LRU Cache | ★★★★ |
| | | |
| | | |