Single Number

Given a non-empty array of integers, every element appears_twice_except for one. Find that single one.

Example

Example 1:

Input:
 [2,2,1]

Output:
 1

Example 2:

Input:
 [4,1,2,1,2]

Output:
 4

Note

使用异或

Code

class Solution {
    public int singleNumber(int[] nums) {
        int res = 0;
        for(int i = 0; i < nums.length; i++)
            res ^= nums[i];
        return res;
    }
}