| 0543 | Diameter of Binary Tree LeetCode XXXX Tree, Depth-First Search, Binary Tree | Easy | | |
| 0124 | Binary Tree Maximum Path Sum LeetCode XXXX Tree, Depth-First Search, Dynamic Programming, Binary Tree | Hard | | |
| 1245 | Tree Diameter LeetCode XXXX Tree, Depth-First Search, Breadth-First Search, Graph, Topological Sort | Medium | | |
| 2246 | Longest Path with Different Adjacent Characters LeetCode XXXX Tree, Depth-First Search, Graph, Topological Sort, Array, String | Hard | | |
| 0687 | Longest Univalue Path LeetCode XXXX Tree, Depth-First Search, Binary Tree | Medium | | |
| 0337 | House Robber III LeetCode XXXX Tree, Depth-First Search, Dynamic Programming, Binary Tree | Medium | | |
| 0333 | Largest BST Subtree | | Tree, Depth-First Search, Binary Search Tree, Dynamic Programming, Binary Tree | Medium |
| 1617 | Count Subtrees with Max Distance Between Cities LeetCode XXXX Bit Manipulation, Tree, Dynamic Programming, State Compression, Enumeration | Hard | | |
| 2538 | Difference Between Maximum and Minimum Price Sum LeetCode XXXX Tree, Depth-First Search, Array, Dynamic Programming | Hard | | |
| 1569 | Number of Ways to Reorder Array to Get Same BST | | Tree, Union Find, Binary Search Tree, Memoization, Array, Mathematics, Divide and Conquer, Dynamic Programming, Binary Tree, Combinatorics | Hard |
| 1372 | Longest ZigZag Path in a Binary Tree | | Tree, Depth-First Search, Dynamic Programming, Binary Tree | Medium |
| 1373 | Maximum Sum BST in Binary Tree | | Tree, Depth-First Search, Binary Search Tree, Dynamic Programming, Binary Tree | Hard |
| 0968 | Binary Tree Cameras LeetCode XXXX Tree, Depth-First Search, Dynamic Programming, Binary Tree | Hard | | |
| 1273 | Delete Tree Nodes | | Tree, Depth-First Search, Breadth-First Search | Medium |
| 1519 | Number of Nodes in the Sub-Tree With the Same Label | | Tree, Depth-First Search, Breadth-First Search, Hash Table, Counting | Medium |