| 839 | Similar String Groups | Hard |
| 841 | Keys and Rooms | Medium |
| 854 | K-Similar Strings | Hard |
| 863 | All Nodes Distance K in Binary Tree | Medium |
| 864 | Shortest Path to Get All Keys | Hard |
| 865 | Smallest Subtree with all the Deepest Nodes | Medium |
| 877 | Shortest Path Visiting All Nodes | Hard |
| 886 | Possible Bipartition | Medium |
| 909 | Snakes and Ladders | Medium |
| 919 | Complete Binary Tree Inserter | Medium |
| 924 | Minimize Malware Spread | Hard |
| 928 | Minimize Malware Spread II | Hard |
| 934 | Shortest Bridge | Medium |
| 958 | Check Completeness of a Binary Tree | Medium |
| 959 | Regions Cut By Slashes | Medium |
| 965 | Univalued Binary Tree | Easy |
| 967 | Numbers With Same Consecutive Differences | Medium |
| 987 | Vertical Order Traversal of a Binary Tree | Hard |
| 993 | Cousins in Binary Tree | Easy |
| 994 | Rotting Oranges | Medium |
| 1020 | Number of Enclaves | Medium |
| 1034 | Coloring A Border | Medium |
| 1036 | Escape a Large Maze | Hard |
| 1042 | Flower Planting With No Adjacent | Medium |
| 1091 | Shortest Path in Binary Matrix | Medium |
| 1096 | Brace Expansion II | Hard |
| 1123 | Lowest Common Ancestor of Deepest Leaves | Medium |
| 1129 | Shortest Path with Alternating Colors | Medium |
| 1161 | Maximum Level Sum of a Binary Tree | Medium |
| 1162 | As Far from Land as Possible | Medium |