Find All Four Sum Numbers Python

PROGRAM TO FIND FOUR ELEMENTS THAT SUM TO A GIVEN VALUE

def findFourElements(arr, n, X):

  

    # Store summs of all pairs in a hash table

    mp = {}

    for i in range(n - 1):

        for j in range(i + 1, n):

            mp[arr[i] + arr[j]] = [i, j]

  

    # Traverse through all pairs and search

    # for X - (current pair summ).

    for i in range(n - 1):

        for j in range(i + 1, n):

            summ = arr[i] + arr[j]

  

            # If X - summ is present in hash table,

            if (X - summ) in mp:

  

                # Making sure that all elements are

                # distinct array elements and an element

                # is not considered more than once.

                p = mp[X - summ]

                if (p[0] != i and p[0] != j and p[1] != i and p[1] != j):

                    print(arr[i], ", ", arr[j], ", ",

                          arr[p[0]], ", ", arr[p[1]], sep="")

                    return

  

  

# Driver code

arr = [10, 20, 30, 40, 1, 2]

n = len(arr)

X = 91

  

# Function call

findFourElements(arr, n, X)







OUTPUT

20, 30, 40, 1

CREDITS: https://www.geeksforgeeks.org/find-four-elements-that-sum-to-a-given-value-set-2/