# Day 1 of 30-Day LeetCode Challenge

Given a **non-empty** array of integers, every element appears *twice* except for one. Find that single one.

class Solution {

public:

int singleNumber(vector<int>& nums) {

int result = nums[0];

for(int i=1;i<nums.size();++i){

result ^= nums[i];

}

return result;

}

};