leetcode--Single Number

Given an array of integers, every element appears twice except for one. Find that single one.

Note:

Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?public class Solution {
public int singleNumber(int[] nums) {
int res = 0;
for(int i=0;i<nums.length;i++){
res ^= nums[i];
}
return res;
}
}