DSA interview prep for campus placements: depth over volume

Most placement coding rounds reward clear thinking on a handful of patterns, not encyclopedic recall. The candidates who do well can explain their approach before they type and can reason about time complexity out loud.

The patterns worth mastering first

• ·Arrays + two pointers + sliding window.
• ·Hashing for lookups and frequency counts.
• ·Recursion → trees → basic graph traversal (BFS/DFS).
• ·Sorting + binary search on the answer.

Practice the explanation, not just the solution

In a real interview you talk while you solve. Practice narrating: restate the problem, state your approach and its complexity, then code. A correct solution delivered in silence scores worse than a slightly slower one you can defend.