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 | 1713 / 1724 | 800 | |
| ABC string | 1461 / 1484 | 800 | |
| Subset sum | 1363 / 1491 | 800 | |
| Subset | 1276 / 1323 | 800 | |
| Permutations | 1007 / 1053 | 800 | |
| Group division | 686 / 749 | 800 | |
| Knight's tour | 648 / 744 | 800 | |
| N-queens problem | 664 / 687 | 800 | |
| Maximum path | 692 / 701 | 800 | |
| Knapsack | 651 / 732 | 800 | |
| Build array | 433 / 452 | 800 | |
| Sudoku | 430 / 458 | 800 | |
| Minesweeper | 200 / 286 | 800 | |
| Travelling Salesman Problem | 394 / 412 | 800 | |
| Word search | 341 / 357 | 800 |