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 | 2112 / 2130 | 800 | |
| ABC string | 1811 / 1838 | 800 | |
| Subset sum | 1660 / 1818 | 800 | |
| Subset | 1539 / 1596 | 800 | |
| Permutations | 1247 / 1297 | 800 | |
| Group division | 844 / 913 | 800 | |
| Knight's tour | 801 / 908 | 800 | |
| N-queens problem | 799 / 823 | 800 | |
| Maximum path | 846 / 854 | 800 | |
| Knapsack | 790 / 878 | 800 | |
| Build array | 521 / 547 | 800 | |
| Sudoku | 508 / 541 | 800 | |
| Minesweeper | 238 / 341 | 800 | |
| Travelling Salesman Problem | 469 / 490 | 800 | |
| Word search | 401 / 416 | 800 |