| 84. Largest Rectangle in Histogram | Solution | Solve | Hard | | |
| 85. Maximal Rectangle | Solution | Solve | Hard | | |
| 88. Merge Sorted Array | Solution | Solve | Easy | | |
| 91. Decode Ways | Solution | Solve | Medium | | |
| 93. Restore IP Addresses | Solution | Solve | Medium | | |
| 98. Validate Binary Search Tree | Solution | Solve | Medium | | |
| 101. Symmetric Tree | Solution | Solve | Easy | | |
| 102. Binary Tree Level Order Traversal | Solution | Solve | Medium | | |
| 103. Binary Tree Zigzag Level Order Traversal | Solution | Solve | Medium | | |
| 112. Path Sum | Solution | Solve | Easy | | |
| 118. Pascal's Triangle | Solution | Solve | Easy | | |
| 119. Pascal's Triangle II | Solution | Solve | Easy | | |
| 120. Triangle | Solution | Solve | Medium | | |
| 121. Best Time to Buy and Sell Stock | Solution | Solve | Easy | | |
| 122. Best Time to Buy and Sell Stock II | Solution | Solve | Medium | | |
| 123. Best Time to Buy and Sell Stock III | Solution | Solve | Hard | | |
| 124. Binary Tree Maximum Path Sum | Solution | Solve | Hard | | |
| 125. Valid Palindrome | Solution | Solve | Easy | | |
| 127. Word Ladder | Solution | Solve | Hard | | |
| 128. Longest Consecutive Sequence | Solution | Solve | Medium | | |
| 130. Surrounded Regions | Solution | Solve | Medium | | |
| 134. Gas Station | Solution | Solve | Medium | | |
| 135. Candy | Solution | Solve | Hard | | |
| 139. Word Break | Solution | Solve | Medium | | |
| 141. Linked List Cycle | Solution | Solve | Easy | | |
| 143. Reorder List | Solution | Solve | Medium | | |
| 146. LRU Cache | Solution | Solve | Medium | | |
| 150. Evaluate Reverse Polish Notation | Solution | Solve | Medium | | |
| 151. Reverse Words in a String | Solution | Solve | Medium | | |
| 152. Maximum Product Subarray | Solution | Solve | Medium | | |
| 153. Find Minimum in Rotated Sorted Array | Solution | Solve | Medium | | |
| 160. Intersection of Two Linked Lists | Solution | Solve | Easy | | |
| 162. Find Peak Element | Solution | Solve | Medium | | |
| 166. Fraction to Recurring Decimal | Solution | Solve | Medium | | |
| 169. Majority Element | Solution | Solve | Easy | | |
| 171. Excel Sheet Column Number | Solution | Solve | Easy | | |
| 188. Best Time to Buy and Sell Stock IV | Solution | Solve | Hard | | |
| 198. House Robber | Solution | Solve | Medium | | |
| 200. Number of Islands | Solution | Solve | Medium | | |
| 204. Count Primes | Solution | Solve | Medium | | |
| 205. Isomorphic Strings | Solution | Solve | Easy | | |
| 206. Reverse Linked List | Solution | Solve | Easy | | |
| 208. Implement Trie (Prefix Tree) | Solution | Solve | Medium | | |
| 209. Minimum Size Subarray Sum | Solution | Solve | Medium | | |
| 210. Course Schedule II | Solution | Solve | Medium | | |
| 215. Kth Largest Element in an Array | Solution | Solve | Medium | | |
| 218. The Skyline Problem | Solution | Solve | Hard | | |
| 221. Maximal Square | Solution | Solve | Medium | | |
| 225. Implement Stack using Queues | Solution | Solve | Easy | | |
| 227. Basic Calculator II | Solution | Solve | Medium | | |
