| 187 | Repeated DNA Sequences | Medium |
| 214 | Shortest Palindrome | Hard |
| 535 | Encode and Decode TinyURL | Medium |
| 572 | Subtree of Another Tree | Easy |
| 705 | Design HashSet | Easy |
| 706 | Design HashMap | Easy |
| 718 | Maximum Length of Repeated Subarray | Medium |
| 1044 | Longest Duplicate Substring | Hard |
| 1251 | Longest Chunked Palindrome Decomposition | Hard |
| 1316 | Distinct Echo Substrings | Hard |
| 1392 | Longest Happy Prefix | Hard |
| 1461 | Check If a String Contains All Binary Codes of Size K | Medium |
| 1923 | Longest Common Subpath | Hard |
| 1948 | Delete Duplicate Folders in System | Hard |
| 1960 | Maximum Product of the Length of Two Palindromic Substrings | Hard |
| 2156 | Find Substring With Given Hash Value | Hard |
| 2223 | Sum of Scores of Built Strings | Hard |
| 2261 | K Divisible Elements Subarrays | Medium |