666 of HDU 5650 so easy water

Test instructions: The sequence of n numbers, the XOR of all sub-sequences, and then the results of all sub-sequences will be different or.

idea: if n. =1 obviously each number appears even several times, then a number of their own or self-evidently 0, if n==1, directly output that number is good ah.

#include <stdio.h>
int main ()
{
	int t;
	scanf ("%d", &t);
	while (t--)
	{
		int n;
		scanf ("%d", &n);
		__int64 res=0;
		for (int i=1;i<=n;i++)
		{
			scanf ("%i64d", &res);
		}
		if (n==1) printf ("%i64d\n", res);
		else printf ("0\n");
	}
	return 0;
}