DSA pattern
Backtracking
Backtracking explores all possible solutions by making choices, exploring consequences, and undoing choices when they lead to invalid states. Essential for generating combinations, permutations, and solving constraint satisfaction problems.
When to use
5 signals- 01Generating all subsets
- 02Generating all permutations
- 03Combination sum problems
- 04N-Queens and Sudoku
- 05Word search in grids
In interviews, call out the pattern early. It helps interviewers follow your reasoning and keeps your implementation focused. After solving, explain tradeoffs in plain language: why this approach is efficient, where it can break, and what edge cases you would test first.
Practice problems
5 listed- 01SubsetsPractice →
- 02PermutationsPractice →
- 03Combination SumPractice →
- 04N-QueensPractice →
- 05Word SearchPractice →
Build a review loop
Treat each pattern as a repeating cycle, not a one-time read. Solve a fresh problem today, revisit the same pattern in 2-3 days, and run one timed attempt at the end of the week. This turns short-term familiarity into reliable recall for live interviews.
When reviewing, re-derive the core steps from scratch before checking a reference solution. If you can explain the state transitions and edge cases clearly, you are much more likely to execute well under interview pressure.