[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[] A) {
int result = 0;
for (int i = 0; i < A.length; i++) {
result = result^A[i];
}
return result;
}
}