| 1 | Two Sum | Solution |
| 7 | Reverse Integer | Solution |
| 9 | Palindrome Number | Solution |
| 13 | Roman to Integer | Solution |
| 14 | Longest Common Prefix | Solution |
| 20 | Valid Parentheses | Solution |
| 21 | Merge Two Sorted Lists | Solution |
| 26 | Remove Duplicates from Sorted Array | Solution |
| 27 | Remove Element | Solution |
| 28 | Implement strStr() | Solution |
| 35 | Search Insert Position | Solution |
| 53 | Maximum Subarray | Solution |
| 58 | Length of Last Word | Solution |
| 67 | Add Binary | Solution |
| 69 | Sqrt(x) | Solution |
| 83 | Remove Duplicates from Sorted List | Solution |
| 88 | Merge Sorted Array | Solution |
| 94 | Binary Tree Inorder Traversal | Solution |
| 100 | Same Tree | Solution |
| 104 | Maximum Depth of Binary Tree | Solution |
| 108 | Convert Sorted Array to Binary Search Tree | Solution |
| 110 | Balanced Binary Tree | Solution |
| 111 | Minimum Depth of Binary Tree | Solution |
| 112 | Path Sum | Solution |
| 118 | Pascal's Triangle | Solution |
| 119 | Pascal's Triangle II |
| 121 | Best Time to Buy and Sell Stock | Solution |
| 136 | Single Number | Solution |
| 141 | Linked List Cycle | Solution |
| 144 | Binary Tree Preorder Traversal | Solution |
| 145 | Binary Tree Postorder Traversal | Solution |
| 169 | Majority Element | Solution |
| 182 | Duplicate Emails | Solution |
| 203 | Remove Linked List Elements | Solution |
| 206 | Reverse Linked List | Solution |
| 217 | Contains Duplicate | Solution |
| 237 | Delete Node in a Linked List | Solution |
| 448 | Find All Numbers Disappeared in an Array |
| 509 | Fibonacci Number | Solution |
| 589 | N-ary Tree Preorder Traversal | Solution |
| 671 | Second Minimum Node In a Binary Tree | Solution |
| 709 | To Lower Case | Solution |
| 1480 | Running Sum of 1d Array | Solution |