samdeepthink

Aug 6, 2026 · Interview Experience

Interview Question: Find the Single Occurring Number in an Array – Three Solutions

The article presents a classic interview problem of locating the unique element in an integer array where every other value appears twice, and walks through three Java 17 implementations—brute‑force double loop, HashMap counting, and a bitwise XOR trick—detailing their time and space trade‑offs and practical considerations.