How to prepare for DSA interviews

Core rule

• Understand the problem first.
• Identify the data structure.
• Think about time and space complexity.
• Write a clean solution.
• Test with edge cases.

Common interview patterns

• Two pointers
• Sliding window
• Prefix sums
• Hash map / frequency counting
• Stack / monotonic stack
• Queue / BFS
• DFS / recursion / backtracking
• Binary search
• Dynamic programming
• Greedy choice
• Graph traversal
• Heap / priority queue

Interview answer structure

When asked a DSA question, answer in this order:

1. Understand the problem.
2. Clarify input and constraints.
3. Choose a data structure.
4. Explain the approach.
5. Write code.
6. Discuss complexity.
7. Mention edge cases.