| 2. Add Two Numbers | Solution | Solve | Medium | | |
| 3. Longest Substring Without Repeating Characters | Solution | Solve | Medium | | |
| 5. Longest Palindromic Substring | Solution | Solve | Medium | | |
| 15. 3Sum | Solution | Solve | Medium | | |
| 17. Letter Combinations of a Phone Number | Solution | Solve | Medium | | |
| 33. Search in Rotated Sorted Array | Solution | Solve | Medium | | |
| 46. Permutations | Solution | Solve | Medium | | |
| 48. Rotate Image | Solution | Solve | Medium | | |
| 49. Group Anagrams | Solution | Solve | Medium | | |
| 50. Pow(x, n) | Solution | Solve | Medium | | |
| 53. Maximum Subarray | Solution | Solve | Medium | | |
| 54. Spiral Matrix | Solution | Solve | Medium | | |
| 55. Jump Game | Solution | Solve | Medium | | |
| 56. Merge Intervals | Solution | Solve | Medium | | |
| 72. Edit Distance | Solution | Solve | Medium | | |
| 75. Sort Colors | Solution | Solve | Medium | | |
| 79. Word Search | Solution | Solve | Medium | | |
| 81. Search in Rotated Sorted Array II | Solution | Solve | Medium | | |
| 128. Longest Consecutive Sequence | Solution | Solve | Medium | | |
| 134. Gas Station | Solution | Solve | Medium | | |
| 146. LRU Cache | Solution | Solve | Medium | | |
| 151. Reverse Words in a String | Solution | Solve | Medium | | |
| 198. House Robber | Solution | Solve | Medium | | |
| 200. Number of Islands | Solution | Solve | Medium | | |
| 230. Kth Smallest Element in a BST | Solution | Solve | Medium | | |
| 236. Lowest Common Ancestor of a Binary Tree | Solution | Solve | Medium | | |
| 238. Product of Array Except Self | Solution | Solve | Medium | | |
| 253. Meeting Rooms II | Solution | Solve | Medium | | |
| 287. Find the Duplicate Number | Solution | Solve | Medium | | |
| 380. Insert Delete GetRandom O(1) | Solution | Solve | Medium | | |
| 394. Decode String | Solution | Solve | Medium | | |
| 468. Validate IP Address | Solution | Solve | Medium | | |
| 486. Predict the Winner | Solution | Solve | Medium | | |
| 498. Diagonal Traverse | Solution | Solve | Medium | | |
| 560. Subarray Sum Equals K | Solution | Solve | Medium | | |
| 567. Permutation in String | Solution | Solve | Medium | | |
| 647. Palindromic Substrings | Solution | Solve | Medium | | |
| 809. Expressive Words | Solution | Solve | Medium | | |
| 877. Stone Game | Solution | Solve | Medium | | |
| 909. Snakes and Ladders | Solution | Solve | Medium | | |
| 986. Interval List Intersections | Solution | Solve | Medium | | |
| 1143. Longest Common Subsequence | Solution | Solve | Medium | | |
| 1443. Minimum Time to Collect All Apples in a Tree | Solution | Solve | Medium | | |
| 2067. Number of Equal Count Substrings | Solution | Solve | Medium | | |
| 2986. Find Third Transaction | Solution | Solve | Medium | | |
| 3047. Find the Largest Area of Square Inside Two Rectangles | Solution | Solve | Medium | | |
| 3648. Minimum Sensors to Cover Grid | Solution | Solve | Medium | | |
| 3607. Power Grid Maintenance | Solution | Solve | Medium | | |
| 3508. Implement Router | Solution | Solve | Medium | | |
