Missing Number

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.

For example,
Given nums = [0, 1, 3] return 2.

Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?

Approach : Use xor of all the nums from 0 to n and elements of nums array.

Because of the property that  i ^ i  = 0, only missing element survives in the end.

1 2 3 4 5 6 7 8 9 10 11 12 13 14

class Solution { public: int missingNumber(vector<int>& nums) { int n = nums.size(); int result = 0; for(int i = 0; i <= n; i++){ result = result ^ i; } for(int i = 0; i < n; i++){ result = result ^ nums[i]; } return result; } };