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 | 2249 / 2270 | 800 | |
| ABC string | 1931 / 1961 | 800 | |
| Subset sum | 1760 / 1923 | 800 | |
| Subset | 1623 / 1687 | 800 | |
| Permutations | 1322 / 1376 | 800 | |
| Group division | 901 / 972 | 800 | |
| Knight's tour | 845 / 957 | 800 | |
| N-queens problem | 840 / 864 | 800 | |
| Maximum path | 882 / 891 | 800 | |
| Knapsack | 824 / 916 | 800 | |
| Build array | 539 / 566 | 800 | |
| Sudoku | 526 / 559 | 800 | |
| Minesweeper | 250 / 358 | 800 | |
| Travelling Salesman Problem | 483 / 507 | 800 | |
| Word search | 414 / 429 | 800 |