| 001 |
Two Sum |
Easy |
Java |
2种方法：暴力 和 HashMap |
| 002 |
Add Two Numbers |
Medium |
Java |
2种方法：模拟 和 递归 |
| 003 |
Longest Substring Without Repeating Characters |
Medium |
Java |
|
| 004 |
Median of Two Sorted Arrays |
Hard |
Java |
4种方法：合并数组，暴力法，二分搜索，划分数组 |
| 005 |
Longest Palindromic Substring |
Medium |
Java |
|
| 010 |
Regular Expression Matching |
Hard |
Java |
|
| 011 |
Container With Most Water |
Medium |
Java |
2 Approaches: BF and Two Pointers with Image Explaination |
| 015 |
3Sum |
Medium |
Java |
3种方法：暴力，Hash，双指针 |
| 017 |
Letter Combinations of a Phone Number |
Medium |
Java |
4 Approaches: BF 4 Loops, Backtracking, BFS, Queue with Image Explaination |
| 019 |
Remove Nth Node From End of List |
Easy |
Java |
|
| 020 |
Valid Parentheses |
Easy |
Java |
|
| 021 |
Merge Two Sorted Lists |
Easy |
Java |
|
| 022 |
Generate Parentheses |
Medium |
Java |
2种方法：暴力法 和 回溯法 |
| 023 |
Merge k Sorted Lists |
Hard |
Java |
|
| 024 |
Swap Nodes in Pairs |
Medium |
Java |
|
| 025 |
Reverse Nodes in k-Group |
Hard |
Java |
|
| 031 |
Next Permutation |
Medium |
Java |
Two Pointers Solution with Detailed Explanation and Code Commented |
| 032 |
Longest Valid Parentheses |
Hard |
Java |
|
| 033 |
Search in Rotated Sorted Array |
Medium |
Java |
|
| 034 |
Search for a Range |
Medium |
Java |
|
| 035 |
Search Insert Position |
Medium |
Java |
|
| 039 |
Combination Sum |
Medium |
Java |
|
| 042 |
Trapping Rain Water |
Hard |
Java |
|
| 045 |
Jump Game II |
Medium |
Java |
|
| 046 |
Permutations |
Medium |
Java |
|
| 048 |
Rotate Image |
Medium |
Java |
|
| 049 |
Group Anagrams |
Medium |
Java |
|
| 053 |
Maximum Subarray |
Medium |
Java |
|
| 055 |
Jump Game |
Medium |
Java |
|
| 056 |
Merge Intervals |
Medium |
Java |
|
| 062 |
Unique Paths |
Medium |
Java |
|
| 064 |
Minimum Path Sum |
Medium |
Java |
|
| 070 |
Climbing Stairs |
Easy |
Java |
|
| 072 |
Edit Distance |
Hard |
Java |
|
| 075 |
Sort Colors |
Medium |
Java |
|
| 076 |
Minimum Window Substring |
Hard |
Java |
|
| 078 |
Subsets |
Medium |
Java |
|
| 079 |
Word Search |
Medium |
Java |
|
| 084 |
Largest Rectangle in Histogram |
Hard |
Java |
|
| 085 |
Maximal Rectangle |
Hard |
Java |
|
| 094 |
Binary Tree Inorder Traversal |
Medium |
Java |
|
| 096 |
Unique Binary Search Trees |
Medium |
Java |
|
| 098 |
Validate Binary Search Tree |
Medium |
Java |
|
| 101 |
Symmetric Tree |
Easy |
Java |
|
| 102 |
Binary Tree Level Order Traversal |
Easy |
Java |
|
| 104 |
Maximum Depth of Binary Tree |
Easy |
Java |
|
| 105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Medium |
Java |
|
| 114 |
Flatten Binary Tree to Linked List |
Medium |
Java |
|
| 121 |
Best Time to Buy and Sell Stock |
Easy |
Java |
|
| 128 |
Longest Consecutive Sequence |
Hard |
Java |
|
| 136 |
Single Number |
Easy |
Java |
|
| 139 |
Word Break |
Medium |
Java |
|
| 141 |
Linked List Cycle |
Easy |
Java |
|
| 142 |
Linked List Cycle II |
Medium |
Java |
|
| 146 |
LRU Cache |
Hard |
Java |
|
| 148 |
Sort List |
Medium |
Java |
|
| 152 |
Maximum Product Subarray |
Medium |
Java |
|
| 155 |
Min Stack |
Easy |
Java |
3种方法：辅助栈，栈，链表 |
| 160 |
Intersection of Two Linked Lists |
Easy |
Java |
|
| 169 |
Majority Element |
Easy |
Java |
|
| 198 |
House Robber |
Easy |
Java |
|
| 200 |
Number of Islands |
Medium |
Java |
|
| 206 |
Reverse Linked List |
Easy |
Java |
|
| 207 |
Course Schedule |
Medium |
Java |
|
| 208 |
Implement Trie (Prefix Tree) |
Medium |
Java |
|
| 210 |
Course Schedule II |
Medium |
Java |
|
| 215 |
Kth Largest Element in an Array |
Medium |
Java |
|
| 221 |
Maximal Square |
Medium |
Java |
|
| 226 |
Invert Binary Tree |
Easy |
Java |
|
| 230 |
Kth Smallest Element in a BST |
Medium |
Java |
|
| 234 |
Palindrome Linked List |
Easy |
Java |
|
| 238 |
Product of Array Except Self |
Medium |
Java |
|
| 239 |
Sliding Window Maximum |
Hard |
Java |
|
| 240 |
Search a 2D Matrix II |
Medium |
Java |
|
| 253 |
Meeting Rooms II |
Medium |
没权限 |
|
| 279 |
Perfect Squares |
Medium |
Java |
|
| 283 |
Move Zeroes |
Easy |
Java |
|
| 287 |
Find the Duplicate Number |
Medium |
Java |
9 Approaches: Count, Hash, Sort, Binary Search, Bit, Fast Slow Pointers |
| 297 |
Serialize and Deserialize Binary Tree |
Hard |
Java |
|
| 300 |
Longest Increasing Subsequence |
Medium |
Java |
|
| 301 |
Remove Invalid Parentheses |
Hard |
Java |
|
| 309 |
Best Time to Buy and Sell Stock with Cooldown |
Medium |
Java |
|
| 312 |
Burst Balloons |
Hard |
Java |
|
| 322 |
Coin Change |
Medium |
Java |
|
| 328 |
Odd Even Linked List |
Medium |
Java |
|
| 337 |
House Robber III |
Medium |
Java |
|
| 338 |
Counting Bits |
Medium |
Java |
|
| 347 |
Top K Frequent Elements |
Medium |
Java |
|
| 394 |
Decode String |
Medium |
Java |
|
| 399 |
Evaluate Division |
Medium |
Java |
|
| 406 |
Queue Reconstruction by Height |
Medium |
Java |
|
| 416 |
Partition Equal Subset Sum |
Medium |
Java |
|
| 437 |
Path Sum III |
Easy |
Java |
|
| 438 |
Find All Anagrams in a String |
Easy |
Java |
滑动窗口：从HashMap，数组，再到统计字母数量之差 |
| 448 |
Find All Numbers Disappeared in an Array |
Easy |
Java |
|
| 461 |
Hamming Distance |
Easy |
Java |
|
| 494 |
Target Sum |
Medium |
Java |
|
| 538 |
Convert BST to Greater Tree |
Easy |
Java |
|
| 543 |
Diameter of Binary Tree |
Easy |
Java |
|
| 560 |
Subarray Sum Equals K |
Medium |
Java |
|
| 572 |
Subtree of Another Tree |
Easy |
Java |
|
| 581 |
Shortest Unsorted Continuous Subarray |
Easy |
Java |
|
| 617 |
Merge Two Binary Trees |
Easy |
Java |
4 Approaches: Recursion, Iteration, BFS and DFS |
| 621 |
Task Scheduler |
Medium |
Java |
|
| 647 |
Palindromic Substrings |
Medium |
Java |
|
| 739 |
Daily Temperatures |
Medium |
Java |
|
| 763 |
Partition Labels |
Medium |
Java |
Illustration of the Max Position of the Char in the Partition with Easy Detailed Explanation |