How to optimally divide an array into two subarrays so that sum of elements in both are same, otherwise give an error?

Question

How to optimally divide an array into two subarrays so that sum of elements in both subarrays is same, otherwise give an error?

Example 1

Given the array

Answer 1

A non optimal solution in python,

from itertools import permutations

def get_splitted_array(a):
  for perm in permutations(a):
    l1 = len(perm)
    for i in range(1, l1):
      if sum(perm[0:i]) == sum(perm[i:l1]):
        return perm[0:i], perm[i:l1]

>>> a = [6,1,3,8]
>>> get_splitted_array(a)
((6, 3), (1, 8))
>>> a = [5,9,20,1,5]
>>> 
>>> get_splitted_array(a)
((5, 9, 1, 5), (20,))
>>>