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 | 2098 / 2116 | 800 | |
| ABC string | 1800 / 1827 | 800 | |
| Subset sum | 1651 / 1807 | 800 | |
| Subset | 1529 / 1586 | 800 | |
| Permutations | 1241 / 1289 | 800 | |
| Group division | 841 / 909 | 800 | |
| Knight's tour | 798 / 904 | 800 | |
| N-queens problem | 796 / 820 | 800 | |
| Maximum path | 844 / 852 | 800 | |
| Knapsack | 789 / 876 | 800 | |
| Build array | 521 / 547 | 800 | |
| Sudoku | 506 / 539 | 800 | |
| Minesweeper | 238 / 341 | 800 | |
| Travelling Salesman Problem | 467 / 488 | 800 | |
| Word search | 401 / 416 | 800 |