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 | 787 / 789 | 800 | |
| ABC string | 652 / 665 | 800 | |
| Subset sum | 648 / 720 | 800 | |
| Subset | 623 / 658 | 800 | |
| Permutations | 425 / 451 | 800 | |
| Group division | 297 / 327 | 800 | |
| Knight's tour | 308 / 362 | 800 | |
| N-queens problem | 316 / 332 | 800 | |
| Maximum path | 315 / 321 | 800 | |
| Knapsack | 287 / 342 | 800 | |
| Build array | 196 / 205 | 800 | |
| Sudoku | 191 / 210 | 800 | |
| Minesweeper | 66 / 101 | 800 | |
| Travelling Salesman Problem | 196 / 208 | 800 | |
| Word search | 154 / 160 | 800 |