leetcode

class Solution {
public:
    int singleNumber(vector<int>& nums) {
         sort(nums.begin(),nums.end());
           int i;
           for(i=0;i<nums.size()-1;i+=2)
           {
               if(nums[i]!=nums[i+1])
                   break;
           }
               return nums[i];
    }
};