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 | 2263 / 2285 | 800 | |
| ABC string | 1944 / 1974 | 800 | |
| Subset sum | 1772 / 1936 | 800 | |
| Subset | 1638 / 1701 | 800 | |
| Permutations | 1333 / 1387 | 800 | |
| Group division | 906 / 979 | 800 | |
| Knight's tour | 850 / 964 | 800 | |
| N-queens problem | 847 / 872 | 800 | |
| Maximum path | 892 / 900 | 800 | |
| Knapsack | 833 / 924 | 800 | |
| Build array | 542 / 569 | 800 | |
| Sudoku | 531 / 564 | 800 | |
| Minesweeper | 253 / 361 | 800 | |
| Travelling Salesman Problem | 484 / 509 | 800 | |
| Word search | 417 / 432 | 800 |