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 index = 1;
for(; index < A.length; ++index){
A[index] = A[index]^A[index-1];
}
return A[index - 1];
}
}