codechef ALEXNUMB - "magic pairs" solution

codechef ALEXNUMB - "magic pairs":http://www.codechef.com/problems/ALEXNUMB

codechef ALEXNUMB - "magic pairs" solution: http://ideone.com/K6W4bu

#include <iostream>

#include <cstdio>

using namespace std;

int main() {

long long int t, n, a;

scanf("%lld", &t);

while(t--) {

scanf("%lld", &n); 

for(int i=0; i<n; i++) scanf("%lld", &a); 

printf("%lld\n", n*(n-1)/2);

}

return 0;

}