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 | 884 / 887 | 800 | |
| ABC string | 735 / 754 | 800 | |
| Subset sum | 720 / 804 | 800 | |
| Subset | 686 / 722 | 800 | |
| Permutations | 479 / 513 | 800 | |
| Group division | 326 / 361 | 800 | |
| Knight's tour | 330 / 391 | 800 | |
| N-queens problem | 340 / 357 | 800 | |
| Maximum path | 349 / 356 | 800 | |
| Knapsack | 317 / 383 | 800 | |
| Build array | 208 / 217 | 800 | |
| Sudoku | 205 / 225 | 800 | |
| Minesweeper | 75 / 117 | 800 | |
| Travelling Salesman Problem | 213 / 226 | 800 | |
| Word search | 164 / 173 | 800 |