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 | 1624 / 1633 | 800 | |
| ABC string | 1381 / 1400 | 800 | |
| Subset sum | 1293 / 1416 | 800 | |
| Subset | 1221 / 1265 | 800 | |
| Permutations | 955 / 1000 | 800 | |
| Group division | 650 / 711 | 800 | |
| Knight's tour | 609 / 702 | 800 | |
| N-queens problem | 635 / 657 | 800 | |
| Maximum path | 658 / 666 | 800 | |
| Knapsack | 620 / 699 | 800 | |
| Build array | 413 / 430 | 800 | |
| Sudoku | 410 / 435 | 800 | |
| Minesweeper | 190 / 270 | 800 | |
| Travelling Salesman Problem | 375 / 391 | 800 | |
| Word search | 326 / 341 | 800 |