Find the single non-repeated element in an array where every other?

Short answer: element appears twice public int SingleNonRepeated(int[] nums) {

Example code

int result = 0;
foreach (int num in nums) {
result ^= num;
}
return result;
} Explanation: XOR of a number with itself is 0; XOR with 0 is the number. So duplicates cancel out, leaving the unique number. Follow on:

Real-world example (ShopNest)

In coding rounds, state complexity aloud, write a clear ShopNest-flavored example (orders, carts), then handle edge cases (empty list, null, overflow).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.