//package com.company;
import java.awt.*;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.*;

public class Main{

    //class to take fast input for CP :)

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(
                    new InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() { return Integer.parseInt(next()); }

        long nextLong() { return Long.parseLong(next()); }

        double nextDouble()
        {
            return Double.parseDouble(next());
        }

        String nextLine()
        {
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }

    //start from here

    public static void main(String[] args) {
        FastReader sc = new FastReader();
        int tt = sc.nextInt();
        for(int t = 0; t < tt ; t++ ){
           int len = sc.nextInt();
           long ans;
           long arr[] = new long[len];
           long sum = 0;
           for(int i= 0 ; i < len ; i ++){
               long temp = sc.nextLong();
               sum += temp;
               arr[i] = temp;
           }
           long mod = sum%len;
           if(sum/len == 0){
               ans = (len-sum)*sum;
           }else{
               if(mod  == 0){
                   ans = 0;
               }else{
                   ans = (len - mod) * mod;
               }
           }
           System.out.println(ans);
        }
    }
}





