Check if there exists two elements in the array whose sum is equal to the sum of the entire array

Question

I've recently started learning python and I have an assignment which I need help with.

Write python code to check if there exist two elements in the array whose sum is equal to the sum of the entire array

Comments

Hahah! Its an assignment and you should do it by yourself. I can help with working around the logic.

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Hahah! Help me out with the logic. That'd be good enough.

Answer 1

You can find the sun of the array. Then for each element in the array a[i], look for a value that is equal to sum - a[i].

Answer 2

You can try something like this Harsh:

def checkPair(a, n):
    s = set()
    sum = 0
    # Find sum of whole array
    for i in range(n):
        sum += a[i]
    # / If sum of array is not
    # even than we can not
    # divide it into two part
    if sum % 2 != 0:
        return False
    sum = sum / 2
    # For each element arr[i], see if
    # there is another element with
    # value sum - arr[i]
    for i in range(n):
        val = sum - a[i]
        if a[i] not in s:
            s.add(a[i])
        # If element exist than
        # return the pair
        if val in s:
            print("Pair elements are",
                  a[i], "and", int(val))
        # Driver Code
a = [2, 11, 5, 1, 4, 7]
n = len(a)
if checkPair(a, n) == False:
    print("No pair found")