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 | 2298 / 2319 | 800 | |
| ABC string | 1975 / 2005 | 800 | |
| Subset sum | 1799 / 1965 | 800 | |
| Subset | 1662 / 1727 | 800 | |
| Permutations | 1347 / 1401 | 800 | |
| Group division | 915 / 989 | 800 | |
| Knight's tour | 862 / 976 | 800 | |
| N-queens problem | 859 / 884 | 800 | |
| Maximum path | 904 / 913 | 800 | |
| Knapsack | 843 / 935 | 800 | |
| Build array | 549 / 577 | 800 | |
| Sudoku | 537 / 570 | 800 | |
| Minesweeper | 256 / 367 | 800 | |
| Travelling Salesman Problem | 490 / 515 | 800 | |
| Word search | 423 / 438 | 800 |