| 652 | Find Duplicate Subtrees | Medium |
| 654 | Maximum Binary Tree | Medium |
| 655 | Print Binary Tree | Medium |
| 658 | Find K Closest Elements | Medium |
| 659 | Split Array into Consecutive Subsequences | Medium |
| 662 | Maximum Width of Binary Tree | Medium |
| 665 | Non-decreasing Array | Medium |
| 667 | Beautiful Arrangement II | Medium |
| 670 | Maximum Swap | Medium |
| 672 | Bulb Switcher II | Medium |
| 673 | Number of Longest Increasing Subsequence | Medium |
| 676 | Implement Magic Dictionary | Medium |
| 677 | Map Sum Pairs | Medium |
| 678 | Valid Parenthesis String | Medium |
| 684 | Redundant Connection | Medium |
| 686 | Repeated String Match | Medium |
| 687 | Longest Univalue Path | Medium |
| 688 | Knight Probability in Chessboard | Medium |
| 690 | Employee Importance | Medium |
| 692 | Top K Frequent Words | Medium |
| 695 | Max Area of Island | Medium |
| 698 | Partition to K Equal Sum Subsets | Medium |
| 701 | Insert into a Binary Search Tree | Medium |
| 707 | Design Linked List | Medium |
| 712 | Minimum ASCII Delete Sum for Two Strings | Medium |
| 713 | Subarray Product Less Than K | Medium |
| 714 | Best Time to Buy and Sell Stock with Transaction Fee | Medium |
| 718 | Maximum Length of Repeated Subarray | Medium |
| 720 | Longest Word in Dictionary | Medium |
| 721 | Accounts Merge | Medium |