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 | 1530 / 1538 | 800 | |
| ABC string | 1294 / 1313 | 800 | |
| Subset sum | 1218 / 1344 | 800 | |
| Subset | 1154 / 1198 | 800 | |
| Permutations | 895 / 937 | 800 | |
| Group division | 613 / 673 | 800 | |
| Knight's tour | 572 / 659 | 800 | |
| N-queens problem | 596 / 617 | 800 | |
| Maximum path | 619 / 627 | 800 | |
| Knapsack | 582 / 657 | 800 | |
| Build array | 388 / 405 | 800 | |
| Sudoku | 383 / 408 | 800 | |
| Minesweeper | 174 / 245 | 800 | |
| Travelling Salesman Problem | 354 / 369 | 800 | |
| Word search | 305 / 319 | 800 |