import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.StringTokenizer;

public class KefaandFirstSteps {


    static long gcd(long a , long b){
        if(a==0)
            return b;
        return gcd(b%a , a);

    }


    static void solve(long [] a , long []b){

        long gcd1 = a[0];
        for (int i = 1; i < a.length; i++) {
            gcd1 = gcd(gcd1 , a[i]);
        }


        long gcd2 = b[0];
        for (int i = 1; i < b.length; i++) {
            gcd2 = gcd(gcd2 , b[i]);
        }


        if(gcd1%gcd2==0 || a.length==1)
            System.out.println("Yes");
        else
            System.out.println("No");


    }


    public static void main(String[] args)  throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);

        int t = Integer.parseInt(br.readLine());
        for(int i = 0 ; i<t ; i++) {

            int n = Integer.parseInt(br.readLine());
            StringTokenizer st = new StringTokenizer(br.readLine());

            long sum = 0;
            while (st.hasMoreTokens()){

                sum += Long.parseLong(st.nextToken());

            }

            System.out.println(sum%n * (n-(sum%n)));

        }
    }



}
