Find Missing Number in Sorted Array of Distinct?

Short answer: Integers int FindMissingNumber(int[] nums) { int low = 0, high = nums.Length - 1; while (low <= high) { int mid = low + (high - low) / 2; if (nums[mid] == mid) low = mid + 1; else high = mid - 1; } return low; } Explanation: In perfect array nums[i] == i; missing number breaks this property, use binary search to find breakpoint. Mathematical Problems

Example code

Integers
int FindMissingNumber(int[] nums)
{
int low = 0, high = nums.Length - 1; while (low <= high) {
int mid = low + (high - low) / 2;
if (nums[mid] == mid)
low = mid + 1; else high = mid - 1;
}
return low;
} Explanation: In perfect array nums[i] == i; missing number breaks this property, use binary search to find breakpoint. Mathematical Problems

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.