| 955 | Delete Columns to Make Sorted II | Medium |
| 966 | Vowel Spellchecker | Medium |
| 972 | Equal Rational Numbers | Hard |
| 981 | Time Based Key-Value Store | Medium |
| 984 | String Without AAA or BBB | Medium |
| 988 | Smallest String Starting From Leaf | Medium |
| 990 | Satisfiability of Equality Equations | Medium |
| 1000 | Delete Columns to Make Sorted III | Hard |
| 1002 | Find Common Characters | Easy |
| 1003 | Check If Word Is Valid After Substitutions | Medium |
| 1016 | Binary String With Substrings Representing 1 To N | Medium |
| 1021 | Remove Outermost Parentheses | Easy |
| 1023 | Camelcase Matching | Medium |
| 1028 | Recover a Tree From Preorder Traversal | Hard |
| 1032 | Stream of Characters | Hard |
| 1041 | Robot Bounded In Circle | Medium |
| 1044 | Longest Duplicate Substring | Hard |
| 1047 | Remove All Adjacent Duplicates In String | Easy |
| 1048 | Longest String Chain | Medium |
| 1061 | Lexicographically Smallest Equivalent String | Medium |
| 1071 | Greatest Common Divisor of Strings | Easy |
| 1078 | Occurrences After Bigram | Easy |
| 1079 | Letter Tile Possibilities | Medium |
| 1081 | Smallest Subsequence of Distinct Characters | Medium |
| 1092 | Shortest Common Supersequence | Hard |
| 1096 | Brace Expansion II | Hard |
| 1106 | Parsing A Boolean Expression | Hard |
| 1108 | Defanging an IP Address | Easy |
| 1111 | Maximum Nesting Depth of Two Valid Parentheses Strings | Medium |
| 1138 | Alphabet Board Path | Medium |