| No. | Title | Mark |
|---|---|---|
| 20 | Valid Parentheses | |
| 32 | Longest Valid Parentheses | |
| 42 | Trapping Rain Water | |
| 84 | Largest Rectangle in Histogram | |
| 85 | Maximal Rectangle | |
| 94 | Binary Tree Inorder Traversal | |
| 114 | Flatten Binary Tree to Linked List | |
| 143 | Reorder List | |
| 144 | Binary Tree Preorder Traversal | |
| 145 | Binary Tree Postorder Traversal | |
| 150 | Evaluate Reverse Polish Notation | |
| 155 | Min Stack | design |
| 173 | Binary Search Tree Iterator | |
| 224 | Basic Calculator | |
| 225 | Implement Stack using Queues | design |
| 232 | Implement Queue using Stacks | design |
| 234 | Palindrome Linked List | |
| 316 | Remove Duplicate Letters | |
| 394 | Decode String | |
| 402 | Remove K Digits | |
| 496 | Next Greater Element I | |
| 503 | Next Greater Element II | |
| 581 | Shortest Unsorted Continuous Subarray | |
| 716 | Max Stack | design |
| 739 | Daily Temperatures | |
| 426 | Convert Binary Search Tree to Sorted Doubly Linked List | |
| 1008 | Construct Binary Search Tree from Preorder Traversal | |
| 1081 | Smallest Subsequence of Distinct Characters | |
| 931 | Maximum Frequency Stack |