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 | 1159 / 1166 | 800 | |
| ABC string | 964 / 981 | 800 | |
| Subset sum | 935 / 1028 | 800 | |
| Subset | 889 / 927 | 800 | |
| Permutations | 647 / 683 | 800 | |
| Group division | 441 / 493 | 800 | |
| Knight's tour | 434 / 505 | 800 | |
| N-queens problem | 448 / 468 | 800 | |
| Maximum path | 470 / 478 | 800 | |
| Knapsack | 427 / 498 | 800 | |
| Build array | 286 / 301 | 800 | |
| Sudoku | 277 / 298 | 800 | |
| Minesweeper | 117 / 170 | 800 | |
| Travelling Salesman Problem | 269 / 282 | 800 | |
| Word search | 220 / 232 | 800 |