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) {
if(A==null || A.length==0){
return 0;
}
int result = A[0];
for(int i=1; i<A.length; i++){
result = result ^ A[i];
}
return result;
}
}