Find the missing number in a sequence from 1 to n using XOR?

public int FindMissingNumber(int[] nums, int n) {
int xor = 0;
for (int i = 1; i <= n; i++) {
xor ^= i;
}
foreach (int num in nums) {
xor ^= num;
}
return xor;
}

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Explanation:

XOR all numbers from 1 to n and XOR all elements in array; duplicates cancel out, leaving

missing number.