Binary Search — DSA Interview Problems

Binary Search is the O(log n) workhorse for sorted data and 'search the answer' problems, and it shows up regularly in technical interviews. Binary search tests precise boundary handling and the insight to binary-search over an answer space, not just an array.

Our library indexes 16 Binary Search problems (4 easy, 10 medium, 2 hard), each solved brute-force → optimal in Java and Python with a line-by-line walkthrough and interview talking points. They're grouped below by the curriculum module that teaches the underlying pattern, so related problems reinforce one another.

If you remember one thing about Binary Search, make it this: If a predicate is monotonic ('is X feasible?'), you can binary-search the smallest/largest X — even when there's no array. Once that clicks, the signature patterns — classic binary search, search on answer, lower/upper bound — start to feel like a checklist you run on every new problem.