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 | 1766 / 1778 | 800 | |
| ABC string | 1517 / 1540 | 800 | |
| Subset sum | 1415 / 1543 | 800 | |
| Subset | 1322 / 1369 | 800 | |
| Permutations | 1052 / 1097 | 800 | |
| Group division | 722 / 785 | 800 | |
| Knight's tour | 678 / 774 | 800 | |
| N-queens problem | 694 / 717 | 800 | |
| Maximum path | 733 / 742 | 800 | |
| Knapsack | 686 / 769 | 800 | |
| Build array | 454 / 476 | 800 | |
| Sudoku | 446 / 475 | 800 | |
| Minesweeper | 206 / 293 | 800 | |
| Travelling Salesman Problem | 408 / 426 | 800 | |
| Word search | 355 / 370 | 800 |