| 403 | Frog Jump | Hard |
| 404 | Sum of Left Leaves | Easy |
| 405 | Convert a Number to Hexadecimal | Easy |
| 406 | Queue Reconstruction by Height | Medium |
| 407 | Trapping Rain Water II | Hard |
| 409 | Longest Palindrome | Easy |
| 410 | Split Array Largest Sum | Hard |
| 412 | Fizz Buzz | Easy |
| 413 | Arithmetic Slices | Medium |
| 414 | Third Maximum Number | Easy |
| 415 | Add Strings | Easy |
| 416 | Partition Equal Subset Sum | Medium |
| 417 | Pacific Atlantic Water Flow | Medium |
| 419 | Battleships in a Board | Medium |
| 420 | Strong Password Checker | Hard |
| 421 | Maximum XOR of Two Numbers in an Array | Medium |
| 423 | Reconstruct Original Digits from English | Medium |
| 424 | Longest Repeating Character Replacement | Medium |
| 427 | Construct Quad Tree | Medium |
| 429 | N-ary Tree Level Order Traversal | Medium |
| 430 | Flatten a Multilevel Doubly Linked List | Medium |
| 432 | All O`one Data Structure | Hard |
| 433 | Minimum Genetic Mutation | Medium |
| 434 | Number of Segments in a String | Easy |
| 435 | Non-overlapping Intervals | Medium |
| 436 | Find Right Interval | Medium |
| 437 | Path Sum III | Medium |
| 438 | Find All Anagrams in a String | Medium |
| 440 | K-th Smallest in Lexicographical Order | Hard |
| 441 | Arranging Coins | Easy |