| 981. Time Based Key-Value Store | | | Solve | Medium | | |
| 984. String Without AAA or BBB | | | Solve | Medium | | |
| 988. Smallest String Starting From Leaf | | | Solve | Medium | | |
| 990. Satisfiability of Equality Equations | | | Solve | Medium | | |
| 1002. Find Common Characters | | | Solve | Easy | | |
| 1003. Check If Word Is Valid After Substitutions | | | Solve | Medium | | |
| 1016. Binary String With Substrings Representing 1 To N | | | Solve | Medium | | |
| 1021. Remove Outermost Parentheses | | | Solve | Easy | | |
| 1023. Camelcase Matching | | | Solve | Medium | | |
| 1028. Recover a Tree From Preorder Traversal | | | Solve | Hard | | |
| 1032. Stream of Characters | | | Solve | Hard | | |
| 1041. Robot Bounded In Circle | | | Solve | Medium | | |
| 1044. Longest Duplicate Substring | | | Solve | Hard | - | |
| 1047. Remove All Adjacent Duplicates In String | | | Solve | Easy | | |
| 1048. Longest String Chain | | | Solve | Medium | | |
| 1055. Shortest Way to Form String | | | Solve | Medium | | |
| 1058. Minimize Rounding Error to Meet Target | | | Solve | Medium | | |
| 1061. Lexicographically Smallest Equivalent String | | | Solve | Medium | | |
| 1062. Longest Repeating Substring | | | Solve | Medium | | |
| 1065. Index Pairs of a String | | | Solve | Easy | | |
| 1071. Greatest Common Divisor of Strings | | | Solve | Easy | | |
| 1078. Occurrences After Bigram | | | Solve | Easy | | |
| 1079. Letter Tile Possibilities | | | Solve | Medium | | |
| 1081. Smallest Subsequence of Distinct Characters | | | Solve | Medium | | |
| 1087. Brace Expansion | | | Solve | Medium | | |
| 1092. Shortest Common Supersequence | | | Solve | Hard | | |
| 1096. Brace Expansion II | | | Solve | Hard | | |
| 1100. Find K-Length Substrings With No Repeated Characters | | | Solve | Medium | | |
| 1106. Parsing A Boolean Expression | | | Solve | Hard | | |
| 1108. Defanging an IP Address | | | Solve | Easy | | |
| 1111. Maximum Nesting Depth of Two Valid Parentheses Strings | | | Solve | Medium | | |
| 1119. Remove Vowels from a String | | | Solve | Easy | | |
| 1138. Alphabet Board Path | | | Solve | Medium | | |
| 1143. Longest Common Subsequence | | | Solve | Medium | | |
| 1147. Longest Chunked Palindrome Decomposition | | | Solve | Hard | | |
| 1153. String Transforms Into Another String | | | Solve | Hard | | |
| 1154. Day of the Year | | | Solve | Easy | | |
| 1156. Swap For Longest Repeated Character Substring | | | Solve | Medium | | |
| 1160. Find Words That Can Be Formed by Characters | | | Solve | Easy | | |
| 1163. Last Substring in Lexicographical Order | | | Solve | Hard | | |
| 1165. Single-Row Keyboard | | | Solve | Easy | | |
| 1166. Design File System | | | Solve | Medium | | |
| 1169. Invalid Transactions | | | Solve | Medium | | |
| 1170. Compare Strings by Frequency of the Smallest Character | | | Solve | Medium | | |
| 1177. Can Make Palindrome from Substring | | | Solve | Medium | | |
| 1178. Number of Valid Words for Each Puzzle | | | Solve | Hard | | |
| 1180. Count Substrings with Only One Distinct Letter | | | Solve | Easy | | |
| 1181. Before and After Puzzle | | | Solve | Medium | | |
| 1189. Maximum Number of Balloons | | | Solve | Easy | | |
| 1190. Reverse Substrings Between Each Pair of Parentheses | | | Solve | Medium | | |