from collections import Counter, defaultdict, deque
import bisect
from sys import stdin, stdout
from itertools import repeat, permutations
import math
import heapq

MOD = 998244353
def inp(force_list=False):
    re = map(int, raw_input().split())
    if len(re) == 1 and not force_list:
        return re[0]
    return re

def inst():
    return raw_input().strip()

def gcd(x, y):
   while(y):
       x, y = y, x % y
   return x

def lcm(x, y):
    return x*y/(gcd(x,y))

def qmod(a, b, mod=MOD):
    res = 1
    while b:
        if b&1:
            res = (res*a)%mod
        b >>= 1
        a = (a*a)%mod
        # print b
    return res

def inv(a):
    return qmod(a, MOD-2)



def my_main():
    kase = inp()
    pans = []

    for _ in range(kase):
        n = inp()
        da = inp(True)
        sm = sum(da)
        left = sm%n
        ans = (n-left)*left
        pans.append(str(ans))


    print '\n'.join(pans)


my_main()
