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from __future__ import print_function # for PyPy2
# from itertools import permutations
# from functools import cmp_to_key  # for adding custom comparator
# from fractions import Fraction
# from collections import *
from sys import stdin
# from bisect import *
from heapq import *
from math import log2, ceil, sqrt, gcd, log
 
g   = lambda : stdin.readline().strip()
gl  = lambda : g().split()
gil = lambda : [int(var) for var in gl()]
gfl = lambda : [float(var) for var in gl()]
gcl = lambda : list(g())
gbs = lambda : [int(var) for var in g()]
rr = lambda x : reversed(range(x)) 
mod = int(1e9)+7
inf = float("inf")
# range = xrange
t, = gil()
for _ in range(t):
    n, = gil()
    a = gil()
    md = sum(a)%n
    print(md*(n-md))
