| Symmetric Tree |
简单 |
| Binary Tree Level Order Traversal |
中等 |
| Binary Tree Zigzag Level Order Traversal |
中等 |
| Binary Tree Level Order Traversal II |
简单 |
| Minimum Depth of Binary Tree |
简单 |
| Word Ladder II |
困难 |
| Word Ladder |
中等 |
| Surrounded Regions |
中等 |
| Clone Graph |
中等 |
| Trapping Rain Water II |
困难 |
| Pacific Atlantic Water Flow |
中等 |
| Find Largest Value in Each Tree Row |
中等 |
| Find Bottom Left Tree Value |
中等 |
| 01 Matrix |
中等 |
| Minesweeper |
中等 |
| Employee Importance |
简单 |
| Cut Off Trees for Golf Event |
困难 |
| Network Delay Time |
中等 |
| Open the Lock |
中等 |
| Sliding Puzzle |
困难 |
| Is Graph Bipartite? |
中等 |
| Cheapest Flights Within K Stops |
中等 |
| Bus Routes |
困难 |
| Remove Invalid Parentheses |
困难 |
| Course Schedule |
中等 |
| Number of Islands |
中等 |
| Binary Tree Right Side View |
中等 |
| Course Schedule II |
中等 |
| Shortest Path Visiting All Nodes |
困难 |
| Perfect Squares |
中等 |
| Minimum Height Trees |
中等 |
| K-Similar Strings |
困难 |
| All Nodes Distance K in Binary Tree |
中等 |
| Shortest Path to Get All Keys |
困难 |
| Maximum Depth of N-ary Tree |
简单 |
| Cat and Mouse |
困难 |
| N-ary Tree Level Order Traversal |
简单 |
| Shortest Bridge |
中等 |