| No. | Title | Mark |
|---|---|---|
| 17 | Letter Combinations of a Phone Number | hot |
| 22 | Generate Parentheses | |
| 37 | Sudoku Solver | |
| 39 | Combination Sum | |
| 40 | Combination Sum II | |
| 46 | Permutations | template |
| 47 | Permutations II | |
| 51 | N-Queens | |
| 52 | N-Queens II | |
| 77 | Combinations | |
| 78 | Subsets | template |
| 79 | Word Search | |
| 90 | Subsets II | |
| 93 | Restore IP Addresses | |
| 95 | Unique Binary Search Trees II | |
| 113 | Path Sum II | |
| 131 | Palindrome Partitioning | |
| 212 | Word Search II | |
| 216 | Combination Sum III | |
| 401 | Binary Watch | |
| 494 | Target Sum | |
| 784 | Letter Case Permutation | |
| 1863 | Sum of All Subset XOR Totals | |
| 813 | All Paths From Source to Target | |
| 1038 | Number of Squareful Arrays |