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

First, if the elements are integers, check that the total is evenly divisible by two- if it isn't success isn't possible.

I would set up the problem as a binary tree, with level 0 deciding which set element 0 goes into, level 1 deciding which set element 1 goes into, etc. At any time if the sum of one set is half the total, you're done- success. At any time if the sum of one set is more than half the total, that sub-tree is a failure and you have to back up. At that point it is a tree traversal problem.