codechef BUYING2 - "buying sweets" solution

codechef BUYING2 - "buying sweets": http://www.codechef.com/problems/BUYING2

codechef BUYING2 - "buying sweets" solution: http://ideone.com/vgD2Hb

#include <iostream>

#include <cstdio>

using namespace std;

int main() {

int t, n, x, b, s, min;

scanf("%d", &t);

while(t--) {

scanf("%d %d", &n, &x);

s=0; min=101;

while(n--) { scanf("%d", &b); s=s+b; if(b<min) min=b; }

if(min<=s%x) printf("-1\n");

else printf("%d\n", s/x);

}

return 0;

}