#include <bits/stdc++.h>
using namespace std;


#define all(v) v.begin(), v.end()
#define intt int32_t
#define int long long
#define endl '\n'

int compute(int l, int r, vector<int> &v, vector<int> &sum, vector<int> &squares)
{
    if(l>r) {
        return 0;
    }
    int rsum = sum[r+1] - sum[l];
    int n = r-l+1;
    int ceilV = ceil((double)rsum/(double)(n));
    int floorV = floor((double)rsum/(double)(n));
    int diff1 = ceilV*n - rsum;
    int diff2 = rsum - floorV*n;
    int V = ((diff1>diff2)?floorV:ceilV);
    return (squares[r+1]-squares[l] + V*V*n - 2*(sum[r+1]-sum[l])*V);
}


void solve()
{
    int n;
    cin >> n;
    vector<int> v(n);
    for(int i = 0; i < n; i++)
        cin >> v[i];
    sort(all(v));
    vector<int> sums(n+1, 0), squares(n+1, 0);
    for(int i = 0; i < n; i++)
    {
        sums[i+1] = sums[i] + v[i];
        squares[i+1] = squares[i] + v[i]*v[i];
    }
    int ans = INT64_MAX;
    for(int i = 0; i < n; i++)
    {
        ans = min(ans, compute(0, i, v, sums, squares) + compute(i+1, n-1, v, sums, squares));
    }
    cout << ans << endl;
}

intt main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cout.precision(numeric_limits<double>::max_digits10);
    int t = 0;
    cin >> t;
    for(int i = 0; i < t; i++)
    {
        // cout << "Case #" << i << ": ";
        solve();
    }
    return 0;

}