| 232 | Implement Queue using Stacks | Easy | 1356 | stackdesignqueue |
| 234 | Palindrome Linked List | Easy | 1281 | linked-listtwo-pointersstack+1 |
| 242 | Valid Anagram | Easy | 1151 | hash-tablestringsorting |
| 252 | Meeting Rooms | Easy | 1163 | arraysorting |
| 258 | Add Digits | Easy | — | mathsimulationnumber-theory |
| 263 | Ugly Number | Easy | — | math |
| 268 | Missing Number | Easy | 1114 | arrayhash-tablemath+2 |
| 278 | First Bad Version | Easy | 1161 | binary-searchinteractive |
| 283 | Move Zeroes | Easy | 1108 | arraytwo-pointers |
| 290 | Word Pattern | Easy | 1294 | hash-tablestring |
| 303 | Range Sum Query - Immutable | Easy | 1185 | arraydesignprefix-sum |
| 326 | Power of Three | Easy | 1250 | mathrecursion |
| 338 | Counting Bits | Easy | 1203 | dynamic-programmingbit-manipulation |
| 342 | Power of Four | Easy | 1286 | mathbit-manipulationrecursion |
| 344 | Reverse String | Easy | — | two-pointersstring |
| 345 | Reverse Vowels of a String | Easy | 1210 | stringtwo-pointers |
| 367 | Valid Perfect Square | Easy | — | mathbinary-search |
| 374 | Guess Number Higher or Lower | Easy | 1100 | binary-searchinteractive |
| 383 | Ransom Note | Easy | 1139 | hash-tablestringcounting |
| 387 | First Unique Character in a String | Easy | — | hash-tablestringqueue+1 |
| 389 | Find the Difference | Easy | 1215 | hash-tablestringbit-manipulation+1 |
| 392 | Is Subsequence | Easy | 1282 | two-pointersstringdynamic-programming |
| 408 | Valid Word Abbreviation | Easy | 1239 | two-pointersstring |
| 409 | Longest Palindrome | Easy | 1132 | hash-tablestringgreedy |
| 412 | Fizz Buzz | Easy | 1134 | mathstringsimulation |
| 415 | Add Strings | Easy | 1307 | stringmathsimulation |
| 441 | Arranging Coins | Easy | 1295 | mathbinary-search |
| 448 | Find All Numbers Disappeared in an Array | Easy | — | arrayhash-table |
| 455 | Assign Cookies | Easy | 1148 | arraygreedysorting+1 |
| 461 | Hamming Distance | Easy | 1085 | bit-manipulation |
| 463 | Island Perimeter | Easy | — | arraydepth-first-searchbreadth-first-search+1 |
| 495 | Teemo Attacking | Easy | 1323 | arraysimulation |
| 496 | Next Greater Element I | Easy | 1318 | arrayhash-tablestack+1 |
| 501 | Find Mode in Binary Search Tree | Easy | — | treedepth-first-searchbinary-search-tree+1 |
| 504 | Base 7 | Easy | 1166 | math |
| 509 | Fibonacci Number | Easy | 1177 | dynamic-programmingmathmemoization+1 |
| 530 | Minimum Absolute Difference in BST | Easy | 1207 | treedepth-first-searchbreadth-first-search+2 |
| 543 | Diameter of Binary Tree | Easy | 1287 | treedepth-first-searchbinary-tree |
| 572 | Subtree of Another Tree | Easy | 1377 | treedepth-first-searchstring-matching+2 |
| 605 | Can Place Flowers | Easy | 1320 | arraygreedy |
| 617 | Merge Two Binary Trees | Easy | — | treedepth-first-searchbreadth-first-search+1 |
| 637 | Average of Levels in Binary Tree | Easy | 1186 | treedepth-first-searchbreadth-first-search+1 |
| 643 | Maximum Average Subarray I | Easy | 1226 | arraysliding-window |
| 680 | Valid Palindrome II | Easy | 1290 | two-pointersstringgreedy |
| 682 | Baseball Game | Easy | — | arraystacksimulation |
| 693 | Binary Number with Alternating Bits | Easy | 1074 | bit-manipulation |
| 700 | Search in a Binary Search Tree | Easy | 1100 | binary-search-treetreerecursion |
| 703 | Kth Largest Element in a Stream | Easy | 1360 | treedesignbinary-search-tree+3 |
| 704 | Binary Search | Easy | 1162 | arraybinary-search |
| 705 | Design HashSet | Easy | — | arrayhash-tablelinked-list+2 |