| 162 | Find Peak Element | Medium | 1536 | arraybinary-search |
| 163 | Missing Ranges | Easy | 1246 | array |
| 167 | Two Sum II - Input Array Is Sorted | Medium | 1389 | arraytwo-pointersbinary-search |
| 168 | Excel Sheet Column Title | Easy | — | mathstring |
| 169 | Majority Element | Easy | 1235 | arrayhash-tabledivide-and-conquer+2 |
| 172 | Factorial Trailing Zeroes | Medium | 1399 | math |
| 173 | Binary Search Tree Iterator | Medium | 1569 | stacktreedesign+3 |
| 179 | Largest Number | Medium | — | arraystringgreedy+1 |
| 187 | Repeated DNA Sequences | Medium | — | hash-tablestringbit-manipulation+3 |
| 188 | Best Time to Buy and Sell Stock IV | Hard | 2037 | arraydynamic-programming |
| 189 | Rotate Array | Medium | 1433 | arraymathtwo-pointers |
| 190 | Reverse Bits | Easy | 1149 | divide-and-conquerbit-manipulation |
| 191 | Number of 1 Bits | Easy | 1088 | divide-and-conquerbit-manipulation |
| 198 | House Robber | Medium | 1514 | arraydynamic-programming |
| 199 | Binary Tree Right Side View | Medium | 1454 | treedepth-first-searchbreadth-first-search+1 |
| 200 | Number of Islands | Medium | 1580 | arraydepth-first-searchbreadth-first-search+2 |
| 201 | Bitwise AND of Numbers Range | Medium | 1604 | bit-manipulation |
| 202 | Happy Number | Easy | 1188 | hash-tablemathtwo-pointers |
| 203 | Remove Linked List Elements | Easy | 1222 | linked-listrecursion |
| 204 | Count Primes | Medium | 1500 | matharraysieve-of-eratosthenes |
| 205 | Isomorphic Strings | Easy | 1262 | hash-tablestring |
| 206 | Reverse Linked List | Easy | 1186 | linked-listrecursion |
| 207 | Course Schedule | Medium | 1656 | depth-first-searchbreadth-first-searchgraph+1 |
| 208 | Implement Trie (Prefix Tree) | Medium | 1543 | hash-tablestringdesign+1 |
| 209 | Minimum Size Subarray Sum | Medium | 1445 | arraybinary-searchsliding-window+1 |
| 210 | Course Schedule II | Medium | 1681 | depth-first-searchbreadth-first-searchgraph+1 |
| 211 | Design Add and Search Words Data Structure | Medium | 1758 | stringdepth-first-searchdesign+1 |
| 212 | Word Search II | Hard | 1976 | arraystringbacktracking+2 |
| 213 | House Robber II | Medium | 1608 | arraydynamic-programming |
| 215 | Kth Largest Element in an Array | Medium | 1508 | arraydivide-and-conquersorting+2 |
| 216 | Combination Sum III | Medium | 1460 | backtrackingarray |
| 217 | Contains Duplicate | Easy | 1160 | arrayhash-tablesorting |
| 218 | The Skyline Problem | Hard | 2452 | arraydivide-and-conquerbinary-search+5 |
| 219 | Contains Duplicate II | Easy | 1320 | arrayhash-tablesliding-window |
| 221 | Maximal Square | Medium | 1638 | arraydynamic-programmingmatrix |
| 222 | Count Complete Tree Nodes | Easy | 1375 | binary-searchtreedepth-first-search+1 |
| 224 | Basic Calculator | Hard | 2010 | mathstringstack+1 |
| 225 | Implement Stack using Queues | Easy | — | stackdesignqueue |
| 226 | Invert Binary Tree | Easy | 1160 | treedepth-first-searchbreadth-first-search+1 |
| 228 | Summary Ranges | Easy | 1192 | array |
| 230 | Kth Smallest Element in a BST | Medium | 1401 | treedepth-first-searchbinary-search-tree+1 |
| 231 | Power of Two | Easy | 1154 | mathbit-manipulationrecursion |
| 232 | Implement Queue using Stacks | Easy | 1356 | stackdesignqueue |
| 234 | Palindrome Linked List | Easy | 1281 | linked-listtwo-pointersstack+1 |
| 235 | Lowest Common Ancestor of a Binary Search Tree | Medium | 1333 | treedepth-first-searchbinary-search-tree+1 |
| 236 | Lowest Common Ancestor of a Binary Tree | Medium | 1660 | treedepth-first-searchbinary-tree |
| 237 | Delete Node in a Linked List | Medium | 1300 | linked-list |
| 238 | Product of Array Except Self | Medium | 1480 | arrayprefix-sum |
| 239 | Sliding Window Maximum | Hard | 1860 | arrayqueuesliding-window+2 |
| 240 | Search a 2D Matrix II | Medium | 1499 | arraybinary-searchdivide-and-conquer+1 |