| 715 | Range Module | Hard |
| 731 | My Calendar II | Medium |
| 732 | My Calendar III | Hard |
| 745 | Prefix and Suffix Search | Hard |
| 855 | Exam Room | Medium |
| 895 | Maximum Frequency Stack | Hard |
| 900 | RLE Iterator | Medium |
| 901 | Online Stock Span | Medium |
| 911 | Online Election | Medium |
| 919 | Complete Binary Tree Inserter | Medium |
| 933 | Number of Recent Calls | Easy |
| 981 | Time Based Key-Value Store | Medium |
| 1032 | Stream of Characters | Hard |
| 1146 | Snapshot Array | Medium |
| 1157 | Online Majority Element In Subarray | Hard |
| 1172 | Dinner Plate Stacks | Hard |
| 1206 | Design Skiplist | Hard |
| 1261 | Find Elements in a Contaminated Binary Tree | Medium |
| 1286 | Iterator for Combination | Medium |
| 1348 | Tweet Counts Per Frequency | Medium |
| 1352 | Product of the Last K Numbers | Medium |
| 1357 | Apply Discount Every n Orders | Medium |
| 1381 | Design a Stack With Increment Operation | Medium |
| 1396 | Design Underground System | Medium |
| 1472 | Design Browser History | Medium |
| 1476 | Subrectangle Queries | Medium |
| 1483 | Kth Ancestor of a Tree Node | Hard |
| 1600 | Throne Inheritance | Medium |
| 1603 | Design Parking System | Easy |
| 1622 | Fancy Sequence | Hard |