#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    vector<long long> v(n);
    for (long long i = 0; i < n; i++) cin >> v[i];
    long long ans = accumulate(v.begin(), v.end(), 0);
    cout << (ans % n) * (n - (ans % n)) << "\n";
  }
}
