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 | 2308 / 2329 | 800 | |
| ABC string | 1986 / 2017 | 800 | |
| Subset sum | 1808 / 1974 | 800 | |
| Subset | 1670 / 1735 | 800 | |
| Permutations | 1353 / 1407 | 800 | |
| Group division | 919 / 995 | 800 | |
| Knight's tour | 867 / 980 | 800 | |
| N-queens problem | 866 / 891 | 800 | |
| Maximum path | 909 / 918 | 800 | |
| Knapsack | 847 / 940 | 800 | |
| Build array | 552 / 580 | 800 | |
| Sudoku | 540 / 573 | 800 | |
| Minesweeper | 257 / 368 | 800 | |
| Travelling Salesman Problem | 492 / 517 | 800 | |
| Word search | 423 / 438 | 800 |