268. 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.

解答：简单的抑或就可以了。

class Solution {
public:
int missingNumber(vector<int>& nums) {
int res1=nums[0];
int res2=0;
for(int i=1;i<nums.size();i++) res1^=nums[i];
for(int i=1;i<=nums.size();i++) res2^=i;
return res1^res2;
}
};