TripletSum.py

# You have been given a random integer array/list(ARR) and a number X. 
# Find and return the number of triplets in the array/list which sum to X.


from sys import stdin

def findTriplet(arr, n, x) :
    #Your code goes here
    count = 0
    for i in range(n):
        for j in range(i+1,n):
            for k in range(j+1,n):
                if arr[i]+arr[j]+arr[k] == x:
                    count += 1
    return count

#Taking Input Using Fast I/O
def takeInput() :
    n = int(stdin.readline().strip())

    if n == 0 :
        return list(), 0

    arr = list(map(int, stdin.readline().strip().split(" ")))
    return arr, n



#main
t = int(stdin.readline().strip())

while t > 0 :

    arr, n = takeInput()
    x = int(stdin.readline().strip())
    print(findTriplet(arr, n, x))
    t -= 1