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 | 2716 / 2738 | 800 | |
| ABC string | 2353 / 2390 | 800 | |
| Subset sum | 2112 / 2295 | 800 | |
| Subset | 1934 / 2002 | 800 | |
| Permutations | 1591 / 1658 | 800 | |
| Group division | 1083 / 1170 | 800 | |
| Knight's tour | 1004 / 1123 | 800 | |
| N-queens problem | 990 / 1020 | 800 | |
| Maximum path | 1034 / 1043 | 800 | |
| Knapsack | 987 / 1092 | 800 | |
| Build array | 632 / 663 | 800 | |
| Sudoku | 617 / 651 | 800 | |
| Minesweeper | 296 / 419 | 800 | |
| Travelling Salesman Problem | 554 / 580 | 800 | |
| Word search | 469 / 487 | 800 |