import java.io.*;
import java.util.*;
public class Main {
    public static void main(String[]  args) {
    FastScanner sc = new FastScanner();
//      Scanner sc = new Scanner(System.in);
       int t=sc.nextInt();
       while (t-->=1){
           int n=sc.nextInt();
           long a[]=sc.readArrayLong(n);
           long sum=0;
           for (long i:a)sum+=i;
           if (sum%n==0){
               System.out.println(0);
           }
           else{
               long x=sum%n;
               x=x*(n-x);
               System.out.println(x);
           }
       }


}

//            out.flush();



    //------------------------------------if-------------------------------------------------------------------------------------------------------------------------------------------------
    //sieve
    static void primeSieve(int a[]){
        //mark all odd number as prime
        for (int i=3;i<a.length;i+=2){
            a[i]=1;
        }
        for (long i=3;i<a.length;i+=2){
            //if the number is marked then it is prime
            if (a[(int) i]==1){
                //mark all muliple of the number as not prime
                for (long j=i*i;j<a.length;j+=i){
                    a[(int)j]=0;

                }
            }
        }
        a[2]=1;
        a[1]=a[0]=0;
    }
    //prime
    static boolean isPrime(int n){
        if (n==2)return true;
        if (n==1)return false;
        for (int i=2;i*i<=n;i++){
            if (n%i==0)return false;
        }
        return true;
    }

    static void sort(int[] a) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : a) l.add(i);
        Collections.sort(l);
        for (int i = 0; i < a.length; i++) a[i] = l.get(i);
    }
    static String sortString(String s) {
        char temp[] = s.toCharArray();
        Arrays.sort(temp);
        return new String(temp);
    }
    static class Pair implements Comparable<Pair> {
        int a;
        int b;


        public Pair(int a, int b) {
            this.a = a;
            this.b = b;

        }
        //        to sort first part
        public int compareTo(Pair other) {
            if (this.a == other.a) return other.b >=this.b ? -1 : 1;
            else if (this.a < other.a) return 1;
            else return -1;
        }
//        public int compareTo(Pair other) {
//            if (this.b == other.b){
//                if (this.a> other.a)return 1;
//                else return -1;
//            }
//            if (this.b > other.b) return 1;
//            else return -1;
//        }
        //sort on the basis of first part only
//        public int compareTo(Pair other) {
//            if (this.a == other.a) return 0;
//             if (this.a > other.a) return 1;
//            else return -1;
//        }

    }
    static int[] frequency(String s){
        int fre[]= new int[26];
        for (int i=0;i<s.length();i++){
            fre[s.charAt(i)-'a']++;
        }
        return fre;
    }
    static long LOWERBOUND(long a[],long k){
        int s=0,e=a.length-1;
        long ans=-1;
        while (s<=e){
            int mid=(s+e)/2;
            if (a[mid]<=k){
                ans=mid;
                s=mid+1;
            }
            else {
                e=mid-1;
            }
        }
        return ans;
    }
    static long mod =(long)(1e9+7);
    static long mod(long x) {
        return ((x % mod + mod) % mod);
    }
    static long div(long a,long b){
        return ((a/b)%mod+mod)%mod;
    }
    static long add(long x, long y) {
        return mod(mod(x) + mod(y));
    }
    static long mul(long x, long y) {
        return mod(mod(x) * mod(y));
    }
    //Fast Power(logN)
    static int fastPower(long a,long n){
        int ans=1;
        while (n>0){
            long lastBit=n&1;
            if (lastBit==1){
                ans=(int)mul(ans,a);
            }

            a=(int)mul(a,a);
            n>>=1;
        }
        return ans;
    }
    static int[] find(int n, int start, int diff) {
        int a[] = new int[n];
        a[0] = start;
        for (int i = 1; i < n; i++) a[i] = a[i - 1] + diff;
        return a;
    }
    static void swap(int a, int b) {
        int c = a;
        a = b;
        b = c;
    }
    static void printArray(int a[]) {
        for (int i = 0; i < a.length; i++) {
            System.out.print(a[i] + " ");
        }
    }
    static boolean sorted(int a[]) {
        int n = a.length;
        boolean flag = true;
        for (int i = 0; i < n - 1; i++) {
            if (a[i] > a[i + 1]) flag = false;
        }
        if (flag) return true;
        else return false;
    }
    public static int findlog(long n) {
        if (n == 0)
            return 0;

        if (n == 1)
            return 0;
        if (n == 2)
            return 1;
        double num = Math.log(n);
        double den = Math.log(2);
        if (den == 0)
            return 0;
        return (int) (num / den);
    }
    public static long gcd(long a, long b) {
        if (b % a == 0)
            return a;
        return gcd(b % a, a);
    }
    public static int gcdInt(int a, int b) {

        if (b % a == 0)
            return a;

        return gcdInt(b % a, a);

    }
    static void sortReverse(int[] a) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int i : a) l.add(i);
        //        Collections.sort.(l);
        Collections.sort(l, Collections.reverseOrder());
        for (int i = 0; i < a.length; i++) a[i] = l.get(i);
    }
    static class FastScanner {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer("");

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

        int nextInt() {
            return Integer.parseInt(next());
        }
        double nextDouble(){
            return Double.parseDouble(next());
        }

        int[] readArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) a[i] = nextInt();
            return a;
        }

        long[] readArrayLong(long n) {
            long[] a = new long[(int) n];
            for (int i = 0; i < n; i++) a[i] = nextLong();
            return a;
        }
        double[] readArrayDouble(long n) {
            double[] a = new double[(int) n];
            for (int i = 0; i < n; i++) a[i] = nextDouble();
            return a;
        }

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