Given an array of integers, every element appears twice except for one. Find that single one.
public class _136 {
public static void main(String[] args) {
int[] nums = {1,2,3,2,5,99,4,5,99,4,1};
int flag = 0;
for (int i = 0; i < nums.length; i++) {
flag = flag ^ nums[i];
}
System.out.println(flag);
}
}