Backtracking
Frequency: 9/10
Many people underestimate this very important technique. Backtracking may be needed for solving the first subtask in OI contest. Moreover, backtracking is a powerful tool for debugging.Resources
Problems
| Binary string | 1730 / 1742 | 800 | |
| ABC string | 1475 / 1499 | 800 | |
| Subset sum | 1377 / 1505 | 800 | |
| Subset | 1285 / 1334 | 800 | |
| Permutations | 1017 / 1062 | 800 | |
| Group division | 694 / 756 | 800 | |
| Knight's tour | 654 / 750 | 800 | |
| N-queens problem | 671 / 695 | 800 | |
| Maximum path | 695 / 704 | 800 | |
| Knapsack | 653 / 735 | 800 | |
| Build array | 434 / 453 | 800 | |
| Sudoku | 433 / 463 | 800 | |
| Minesweeper | 200 / 286 | 800 | |
| Travelling Salesman Problem | 395 / 412 | 800 | |
| Word search | 344 / 359 | 800 |