| 647 | Palindromic Substrings | Medium | 1525 | two-pointersstringdynamic-programming |
| 648 | Replace Words | Medium | 1410 | triehash-tablestring |
| 649 | Dota2 Senate | Medium | 1530 | queuegreedy |
| 652 | Find Duplicate Subtrees | Medium | — | hash-tabletreedepth-first-search+1 |
| 654 | Maximum Binary Tree | Medium | — | arraydivide-and-conquerstack+3 |
| 658 | Find K Closest Elements | Medium | 1702 | arraytwo-pointersbinary-search+2 |
| 662 | Maximum Width of Binary Tree | Medium | — | treedepth-first-searchbreadth-first-search+1 |
| 665 | Non-decreasing Array | Medium | — | array |
| 669 | Trim a Binary Search Tree | Medium | — | treedepth-first-searchbinary-search-tree+1 |
| 673 | Number of Longest Increasing Subsequence | Medium | — | arraydynamic-programmingbinary-indexed-tree+1 |
| 676 | Implement Magic Dictionary | Medium | 1480 | hash-tablestringdepth-first-search+1 |
| 677 | Map Sum Pairs | Medium | 1445 | triehash-tabledesign |
| 678 | Valid Parenthesis String | Medium | 1700 | stringdynamic-programmingstack+1 |
| 680 | Valid Palindrome II | Easy | 1290 | two-pointersstringgreedy |
| 682 | Baseball Game | Easy | — | arraystacksimulation |
| 684 | Redundant Connection | Medium | 1597 | depth-first-searchbreadth-first-searchunion-find+1 |
| 685 | Redundant Connection II | Hard | 1897 | depth-first-searchbreadth-first-searchunion-find+1 |
| 686 | Repeated String Match | Medium | — | stringstring-matching |
| 691 | Stickers to Spell Word | Hard | — | arrayhash-tablestring+5 |
| 692 | Top K Frequent Words | Medium | — | arrayhash-tablestring+5 |
| 693 | Binary Number with Alternating Bits | Easy | 1074 | bit-manipulation |
| 695 | Max Area of Island | Medium | 1470 | arraydepth-first-searchbreadth-first-search+2 |
| 698 | Partition to K Equal Sum Subsets | Medium | 1677 | backtrackingbit-manipulationdynamic-programming |
| 699 | Falling Squares | Hard | — | arraysegment-treeordered-set |
| 700 | Search in a Binary Search Tree | Easy | 1100 | binary-search-treetreerecursion |
| 701 | Insert into a Binary Search Tree | Medium | — | treebinary-search-treebinary-tree |
| 703 | Kth Largest Element in a Stream | Easy | 1360 | treedesignbinary-search-tree+3 |
| 704 | Binary Search | Easy | 1162 | arraybinary-search |
| 705 | Design HashSet | Easy | — | arrayhash-tablelinked-list+2 |
| 706 | Design HashMap | Easy | — | arrayhash-tablelinked-list+2 |
| 707 | Design Linked List | Medium | — | linked-listdesign |
| 713 | Subarray Product Less Than K | Medium | 1539 | arraysliding-windowprefix-sum |
| 714 | Best Time to Buy and Sell Stock with Transaction Fee | Medium | 1675 | dynamic-programminggreedyarray |
| 715 | Range Module | Hard | — | designsegment-treeordered-set |
| 719 | Find K-th Smallest Pair Distance | Hard | 1983 | arraytwo-pointersbinary-search+1 |
| 720 | Longest Word in Dictionary | Medium | 1355 | triehash-tablesorting+1 |
| 721 | Accounts Merge | Medium | 1664 | arrayhash-tablestring+4 |
| 724 | Find Pivot Index | Easy | 1204 | arrayprefix-sum |
| 725 | Split Linked List in Parts | Medium | — | linked-list |
| 729 | My Calendar I | Medium | — | arraybinary-searchdesign+2 |
| 731 | My Calendar II | Medium | — | arraybinary-searchdesign+3 |
| 732 | My Calendar III | Hard | — | binary-searchdesignsegment-tree+2 |
| 733 | Flood Fill | Easy | 1139 | arraydepth-first-searchbreadth-first-search+1 |
| 735 | Asteroid Collision | Medium | 1550 | stackarraysimulation |
| 739 | Daily Temperatures | Medium | 1418 | arraystackmonotonic-stack |
| 740 | Delete and Earn | Medium | — | arrayhash-tabledynamic-programming |
| 743 | Network Delay Time | Medium | 1648 | depth-first-searchbreadth-first-searchgraph+2 |
| 745 | Prefix and Suffix Search | Hard | 2002 | hash-tablestringdesign+1 |
| 746 | Min Cost Climbing Stairs | Easy | 1167 | arraydynamic-programming |
| 752 | Open the Lock | Medium | 1878 | arrayhash-tablestring+1 |