| 124. Binary Tree Maximum Path SumOpen source | Hard | Dynamic ProgrammingTreeDepth-First Search+2 more |
| 125. Valid PalindromeOpen source | Easy | Two PointersString |
| 127. Word LadderOpen source | Hard | Hash TableStringBreadth-First Search+1 more |
| 128. Longest Consecutive SequenceOpen source | Medium | ArrayHash TableUnion-Find |
| 130. Surrounded RegionsOpen source | Medium | ArrayDepth-First SearchBreadth-First Search+2 more |
| 131. Palindrome PartitioningOpen source | Medium | StringDynamic ProgrammingBacktracking |
| 133. Clone GraphOpen source | Medium | Hash TableDepth-First SearchBreadth-First Search+1 more |
| 134. Gas StationOpen source | Medium | ArrayGreedy |
| 135. CandyOpen source | Hard | ArrayGreedy |
| 136. Single NumberOpen source | Easy | ArrayBit Manipulation |
| 138. Copy List with Random PointerOpen source | Medium | Hash TableLinked List |
| 139. Word BreakOpen source | Medium | ArrayHash TableString+4 more |
| 140. Word Break IIOpen source | Hard | ArrayHash TableString+4 more |
| 141. Linked List CycleOpen source | Easy | Hash TableLinked ListTwo Pointers+1 more |
| 143. Reorder ListOpen source | Medium | Linked ListTwo PointersStack+1 more |
| 144. Binary Tree Preorder TraversalOpen source | Easy | StackTreeDepth-First Search+1 more |
| 145. Binary Tree Postorder TraversalOpen source | Easy | StackTreeDepth-First Search+1 more |
| 146. LRU CacheOpen source | Medium | Hash TableLinked ListDesign+1 more |
| 150. Evaluate Reverse Polish NotationOpen source | Medium | ArrayMathStack |
| 152. Maximum Product SubarrayOpen source | Medium | ArrayDynamic Programming |
| 153. Find Minimum in Rotated Sorted ArrayOpen source | Medium | ArrayBinary Search |
| 155. Min StackOpen source | Medium | StackDesign |
| 167. Two Sum II - Input Array Is SortedOpen source | Medium | ArrayTwo PointersBinary Search |
| 168. Excel Sheet Column TitleOpen source | Easy | MathString |
| 169. Majority ElementOpen source | Easy | ArrayHash TableDivide and Conquer+3 more |