| # | Date | Title | Solution | Difficulty |
|---|---|---|---|---|
| 1 | 2021-02-20 | Two Sum | java | |
| 2 | 2018-07-15 | Add Two Numbers | java | Medium |
| 3 | 2022-01-25 | Longest Substring Without Repeating Characters | java | Medium |
| 5 | 2022-01-27 | Longest Palindromic Substring | java | Medium |
| 6 | 2022-01-29 | Zigzag Conversion | java | Medium |
| 7 | 2022-02-02 | Reverse Integer | java | Medium |
| 8 | 2022-02-06 | String to Integer (atoi) | java | Medium |
| 9 | 2020-03-17 | Palindrome Number | java | |
| 11 | 2020-05-27 | Container With Most Water | java | |
| 12 | 2022-02-10 | Integer to Roman | java | |
| 13 | 2020-03-21 | Roman to Integer | java | |
| 14 | 2020-03-24 | Longest Common Prefix | java | |
| 15 | 2022-02-11 | 3Sum | java | |
| 16 | 2022-02-11 | 3Sum Closest | java | |
| 17 | 2022-02-16 | Letter Combinations of a Phone Number | java | |
| 18 | 2022-02-17 | 4Sum | java | |
| 19 | 2022-02-17 | Remove Nth Node From End of List | java | |
| 20 | 2020-03-24 | Valid Parentheses | java | |
| 21 | 2022-02-06 | Merge Two Sorted Lists | java | Easy |
| 22 | 2022-02-22 | Generate Parentheses | java | Medium |
| 24 | 2021-02-28 | Swap Nodes in Pairs | java | Medium |
| 26 | 2021-01-21 | Remove Duplicates From Sorted Array | java | |
| 27 | 2022-02-22 | Remove Element | java | |
| 28 | 2022-02-23 | Implement strStr() | java | |
| 29 | 2022-02-28 | Divide Two Integers | java | Medium |
| 31 | 2022-02-28 | Next Permutation | java | Medium❌ |
| 33 | 2020-04-19 | Search in Rotated Sorted Array | java | |
| 34 | 2022-03-08 | Find First and Last Position of Element in Sorted Array | java | |
| 35 | 2022-03-04 | Search Insert Position | java | Medium |
| 36 | 2021-02-19 | Valid Sudoku | java | Medium |
| 38 | 2022-03-13 | Count and Say | java | Medium |
| 39 | 2022-03-13 | Combination Sum | java | Medium |
| 40 | 2022-03-14 | Combination Sum II | java | Medium❌ |
| 43 | 2022-03-22 | Multiply Strings | java | Medium❌ |
| 45 | 2022-03-26 | Jump Game II | java | Medium |
| 46 | 2022-04-10 | Permutations | java | Medium |
| 47 | 2022-04-10 | Permutations II | java | Medium❌ |
| 48 | 2022-04-10 | Rotate Image | java | Medium |
| 49 | 2020-04-06 | Group Anagrams | java | |
| 53 | 2020-04-03 | Maximum Subarray | java | Easy |
| 54 | 2022-04-13 | Spiral Matrix | java | Medium |
| 55 | 2020-04-25 | Jump Game | java | |
| 56 | 2022-04-13 | Merge Intervals | java | Medium |
| 57 | 2022-04-13 | Insert Interval | java | Medium |
| 58 | 2022-03-20 | Length of Last Word | java | Easy |
| 59 | 2022-04-23 | Spiral Matrix II | java | Medium |
| 61 | 2022-04-28 | Rotate List | java | Medium 🌟 |
| 62 | 2022-04-28 | Unique Paths | java | Medium |
| 63 | 2022-04-28 | Unique Paths II | java | Medium |
| 64 | 2020-04-18 | Minimum Path Sum | java | Medium |
| 66 | 2021-02-04 | Plus One | java | |
| 67 | 2021-03-20 | Add Binary | java | Easy ❌ |
| 69 | 2021-03-20 | Sqrt(x) | java | Easy |
| 71 | 2022-05-15 | Simplify Path | java | Medium ❌ |
| 72 | 2020-05-31 | Edit Distance | java | Hard |
| 73 | 2022-05-15 | Set Matrix Zeroes | java | Medium |
| 74 | 2022-05-15 | Search a 2D Matrix | java | Medium ❌ |
| 75 | 2022-05-26 | Sort Colors | java | Medium |
| 77 | 2022-05-28 | Combinations | java | Medium |
| 78 | 2021-03-29 | Subsets | java | |
| 79 | 2022-06-12 | Word Search | java | |
| 80 | 2022-06-12 | Remove Duplicates from Sorted Array II | java | |
| 81 | 2022-06-12 | Search in Rotated Sorted Array II | java | ❌ |
| 82 | 2020-08-14 | Remove Duplicates from Sorted List II | java | Medium |
| 83 | 2022-04-03 | Remove Duplicates from Sorted List | java | Easy |
| 86 | 2022-06-22 | Partition List | java | Medium |
| 88 | 2022-04-03 | Merge Sorted Array | java | Easy |
| 89 | 2022-06-26 | Gray Code | java | Medium ❌ |
| 90 | 2022-06-26 | Subsets II | java | Medium ❌ |
| 91 | 2022-08-28 | Decode Ways | java | Medium ❌ |
| 92 | 2020-08-13 | Reverse Linked List II | java | Medium |
| 93 | 2022-08-10 | Restore IP Addresses | java | Medium |
| 94 | 2019-04-16 | Binary Tree Inorder Traversal | java | |
| 95 | 2022-08-04 | Unique Binary Search Trees II | java | Medium |
| 96 | 2022-08-04 | Unique Binary Search Trees | java | Medium ❌ |
| 97 | 2022-07-19 | Interleaving String | java | Medium ❌ |
| 98 | 2022-07-17 | Validate Binary Search Tree | java | Medium |
| 99 | 2022-07-10 | Recover Binary Search Tree | java | Medium |
| 100 | 2022-04-03 | Same Tree | java | Easy |
| 101 | 2022-04-24 | Symmetric Tree | java | Easy |
| 103 | 2021-03-19 | Binary Tree Zigzag Level Order Traversal | java | |
| 104 | 2021-03-16 | Maximum Depth of Binary Tree | java | |
| 108 | 2022-04-24 | Convert Sorted Array to Binary Search Tree | java | |
| 109 | 2020-08-18 | Convert Sorted List to Binary Search Tree | java | |
| 110 | 2022-05-08 | Balanced Binary Tree | java | |
| 111 | 2021-03-19 | Minimum Depth of Binary Tree | java | |
| 112 | 2022-05-08 | Path Sum | java | |
| 118 | 2022-05-08 | Pascal's Triangle | java | |
| 119 | 2022-05-22 | Pascal's Triangle II | java | |
| 121 | 2021-04-07 | Best Time to Buy and Sell Stock | java | |
| 122 | 2021-01-19 | Best Time To Buy And Sell Stock II | java | |
| 123 | 2021-04-07 | Best Time to Buy and Sell Stock III | java | |
| 124 | 2020-04-29 | Binary Tree Maximum Path Sum | java | |
| 125 | 2020-05-22 | Valid Palindrome | java | |
| 141 | 2022-07-03 | Linked List Cycle | java | |
| 144 | 2020-06-05 | Binary Tree Preorder Traversal | java | |
| 145 | 2020-06-05 | Binary Tree Postorder Traversal | java | |
| 146 | 2020-04-24 | LRU Cache | java | |
| 160 | 2022-07-03 | Intersection of Two Linked Lists | java | |
| 168 | 2023-12-17 | Excel Sheet Column Title | java | Easy |
| 169 | 2020-05-06 | Majority Element | java | |
| 136 | 2020-04-01 | Single Number | java | |
| 155 | 2020-04-10 | Min Stack | java | |
| 171 | 2022-09-04 | Excel Sheet Column Number | java | Easy |
| 200 | 2020-04-17 | Number of Islands | java | |
| 200 | 2021-03-23 | Number of Islands | java | |
| 201 | 2020-04-23 | Bitwise AND of Numbers Range | java | |
| 202 | 2020-04-02 | Happy Number | java | |
| 203 | 2020-08-17 | Remove Linked List Elements | java | Easy |
| 208 | 2020-05-14 | Implement Trie (Prefix Tree) | java | |
| 207 | 2020-05-31 | Course Schedule | java | |
| 217 | 2021-02-02 | Contains Duplicate | java | |
| 219 | 2023-12-24 | Contains Duplicate II | java | Easy |
| 221 | 2020-04-27 | Maximal Square | java | Medium |
| 222 | 2023-12-24 | Count Complete Tree Nodes | java | Easy |
| 226 | 2023-12-24 | Invert Binary Tree | java | Easy |
| 228 | 2023-12-17 | Summary Ranges | java | Easy |
| 230 | 2019-04-24 | Kth Smallest Element in a BST | java | |
| 230 | 2020-05-20 | Kth Smallest Element in a BST | java | |
| 238 | 2020-04-15 | Product of Array Except Self | java | |
| 242 | 2021-02-28 | Valid Anagram | java | |
| 236 | 2021-03-17 | Lowest Common Ancestor of a Binary Tree | java | |
| 278 | 2020-05-01 | First Bad Version | java | |
| 283 | 2021-02-07 | Move Zeroes | java | |
| 283 | 2020-04-04 | Move Zeroes | java | |
| 328 | 2020-05-16 | Odd Even Linked List | java | Medium |
| 338 | 2020-05-28 | Counting Bits | java | Medium |
| 350 | 2021-02-03 | Intersection Of Two Arrays II | java | |
| 367 | 2020-05-09 | Valid Perfect Square | java | |
| 387 | 2020-05-05 | First Unique Character in a String | java | |
| 383 | 2020-05-03 | Ransom Note | java | |
| 441 | 2021-03-04 | Arranging Coins | java | |
| 451 | 2020-05-22 | Sort Characters By Frequency | java | |
| 438 | 2020-05-17 | Find All Anagrams in a String | java | |
| 402 | 2020-05-13 | Remove K Digits | java | |
| 476 | 2020-05-04 | Number Complement | java | |
| 525 | 2020-04-13 | Contiguous Array | java | |
| 543 | 2020-04-11 | Diameter of Binary Tree | java | |
| 560 | 2020-04-22 | Subarray Sum Equals K | java | |
| 567 | 2020-05-18 | Permutation in String | java | |
| 692 | 2021-03-18 | Top K Frequent Words | java | |
| 678 | 2020-04-16 | Valid Parenthesis String | java | |
| 703 | 2021-03-24 | Kth Largest Element in a Stream | java | |
| 714 | 2021-03-29 | Best Time to Buy and Sell Stock with Transaction Fee | java | |
| 767 | 2021-01-06 | Reorganize String | java | |
| 733 | 2020-05-12 | Single Element in a Sorted Array | java | |
| 733 | 2020-05-11 | Flood Fill | java | |
| 771 | 2020-05-02 | Jewels and Stones | java | |
| 783 | 2021-03-19 | Minimum Distance Between BST Nodes | java | |
| 789 | 2019-09-01 | Escape The Ghosts | java | |
| 844 | 2020-04-09 | Backspace String Compare | java | |
| 807 | 2019-04-14 | Max Increase to Keep City Skyline | java | |
| 876 | 2020-04-08 | Middle of the Linked List | java | Easy |
| 886 | 2020-05-27 | Possible Bipartition | java | |
| 901 | 2020-05-19 | Online Stock Span | java | |
| 918 | 2020-05-15 | Maximum Sum Circular Subarray | java | |
| 938 | 2021-03-19 | Range Sum of BST | java | |
| 973 | 2020-05-30 | K Closest Points to Origin | java | |
| 986 | 2020-05-23 | Interval List Intersections | java | |
| 993 | 2020-05-07 | Cousins in Binary Tree | java | |
| 997 | 2020-05-10 | Find the Town Judge | java | |
| 1008 | 2020-04-20 | Construct Binary Search Tree from Preorder Traversal | java | |
| 1021 | 2021-03-04 | Remove Outermost Parentheses | java | |
| 1035 | 2020-05-25 | Uncrossed Lines | java | Medium |
| 1046 | 2020-04-12 | Last Stone Weight | java | |
| 1047 | 2021-03-04 | Remove All Adjacent Duplicates In String | java | |
| 1143 | 2020-04-26 | Longest Common Subsequence | java | Medium |
| 1232 | 2020-05-08 | Check If It Is a Straight Line | java | |
| 1277 | 2020-05-21 | Count Square Submatrices with All Ones | java | Medium |
| 2109 | 2022-05-27 | Adding Spaces to a String | java | Medium |
| # | 2020-04-30 | Check String Is a Valid Sequence | java | |
| # | 2020-04-28 | First Unique Number | java | |
| # | 2020-04-21 | Leftmost Column with at Least a One | java | |
| # | 2020-04-07 | Counting Elements | java | |
| # | 2020-04-15 | Perform String Shifts | java | |
| # | 2022-08-12 | Sort Book Chapters | java |
TODOList
| # | Date | Title | Solution | * |
|---|---|---|---|---|
| 189 | 2021-01-22 | Rotate Array | java | |
| 1018 | 2021-01-14 | Prefixes Div By 5 | java | |
| 127 | 2021-01-07 | Word Ladder | java | |
| 1203 | 2021-01-12 | Sort Items | java | |
| 684 | 2021-01-13 | Redundant Connection | java | |
| 28 | 2021-02-19 | Rotate Image | java | |
| 50 | 2021-03-04 | Pow(x, n) | java | |
| 210 | 2021-03-23 | Course Schedule II | java | |
| 872 | 2021-03-29 | Leaf-Similar Trees | java | |
| 563 | 2021-03-29 | Binary Tree Tilt | java | |
| 198 | 2021-03-29 | House Robber | java | |
| 70 | 2021-03-29 | Climbing Stairs | java | |
| 784 | 2021-03-29 | Letter Case Permutation | java | |
| 455 | 2021-03-29 | Assign Cookies | java | |
| 720 | 2021-03-29 | Longest Word in Dictionary | java | |
| 102 | 2021-03-29 | Binary Tree Level Order Traversal | java | |
| 429 | 2021-03-29 | N-ary Tree Level Order Traversal | java | |
| 208 | 2021-03-29 | Implement Trie (Prefix Tree) | java |