ICPC0108 - SUM TRIPLE ZERO

t = int(input())
for k in range(0,t):
	n = int(input())
	a = sorted(list(map(int,input().split())))
	dem = 0
	for i in range(0,len(a)-2):
		l=i+1
		r=len(a)-1
		x = a[i]
		while l<r:
			if x+a[l]+a[r]==0:
				dem+=1
				l+=1
			elif x+a[l]+a[r]<0:
				l+=1
			else: 
				r-=1
	print(dem)