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 | 1568 / 1577 | 800 | |
| ABC string | 1329 / 1349 | 800 | |
| Subset sum | 1250 / 1375 | 800 | |
| Subset | 1183 / 1227 | 800 | |
| Permutations | 920 / 963 | 800 | |
| Group division | 626 / 686 | 800 | |
| Knight's tour | 585 / 675 | 800 | |
| N-queens problem | 611 / 633 | 800 | |
| Maximum path | 634 / 642 | 800 | |
| Knapsack | 598 / 673 | 800 | |
| Build array | 399 / 416 | 800 | |
| Sudoku | 395 / 420 | 800 | |
| Minesweeper | 181 / 257 | 800 | |
| Travelling Salesman Problem | 362 / 378 | 800 | |
| Word search | 318 / 333 | 800 |