| 501 | Find Mode in Binary Search Tree | Easy | tree |
| 508 | Most Frequent Subtree Sum | Medium | tree |
| 513 | Find Bottom Left Tree Value | Medium | tree |
| 558 | Logical OR of Two Binary Grids Represented as Quad-Trees | Medium | tree |
| 559 | Max Consecutive Ones | Easy | tree |
| 589 | N-ary Tree Preorder Traversal | Easy | tree |
| 590 | N-ary Tree Postorder Traversal | Medium | tree |
| 700 | Search in a Binary Search Tree | Easy | tree |
| 701 | Insert into a Binary Search Tree | Medium | tree |
| 1361 | Validate Binary Tree Nodes | Medium | graph |
| 1916 | Count Ways to Build Rooms in an Ant Colony | Hard | math |
| 2236 | Root Equals Sum of Children | Easy | tree |
| 2265 | Count Nodes Equal to Average of Subtree | Medium | depth first search |
| 2277 | Closest Node to Path in Tree | Hard | tree |
| 2322 | Minimum Score After Removals on a Tree | Hard | depth first search |
| 2445 | Number of Nodes With Value One | Medium | depth first search |
| 2458 | Height of Binary Tree After Subtree Removal Queries | Hard | depth first search |
| 2467 | Most Profitable Path in a Tree | Medium | depth first search |
| 2477 | Minimum Fuel Cost to Report to the Capital | Medium | depth first search |
| 2509 | Cycle Length Queries in a Tree | Hard | tree |
| 2581 | Count Number of Possible Root Nodes | Hard | depth first search |
| 2603 | Collect Coins in a Tree | Hard | breadth first search |
| 2673 | Make Costs of Paths Equal in a Binary Tree | Medium | greedy |
| 2773 | Height of Special Binary Tree | Medium | depth first search |
| 2791 | Count Paths That Can Form a Palindrome in a Tree | Hard | depth first search |
| 2846 | Minimum Edge Weight Equilibrium Queries in a Tree | Hard | tree |
| 3553 | Minimum Weighted Subgraph With the Required Paths II | Hard | tree |
| 3558 | Number of Ways to Assign Edge Weights I | Medium | tree |
| 3559 | Number of Ways to Assign Edge Weights II | Medium | tree |
| 3585 | Find Weighted Median Node in Tree | Hard | tree |
| 3715 | Sum of Perfect Square Ancestors | Hard | tree |