Split the array into equal sum parts according to given conditions in C++

Here we will see one problem. Suppose one array arr is given. We have to check whether the array can be split into two parts, such that −

Sub of both sub-arrays will be the same
All elements, which are multiple of 5, will be in the same group
All elements which are multiple of 3, but not multiple of 5, will be in the same group
All other elements will be in other groups.

Suppose the array elements are {1, 4, 3}, then this can be split, because the sum of {1, 3} is the same as the sum of {4}, and the groups are also correct for the given condition.

Algorithm

isSplitArray(arr, n, start, left_sum, right_sum) −

Begin
   if start = n, then return true when left_sum = right_sum, otherwise false
   if arr[start] is divisible by 5, then add arr[start] with the left_sum
   else if arr[start] is divisible by 3, then add arr[start] with the right_sum
   else
      return isSplitArray(arr, n, start + 1, left_sum + arr[start], right_sum) OR isSplitArray(arr, n, start + 1, left_sum, right_sum + arr[start])
   isSplitArray(arr, n, start + 1, left_sum, right_sum)
End

Example

Live Demo

#include <iostream>
using namespace std;
bool isSplitArray(int* arr, int n, int start, int left_sum, int right_sum) {
   if (start == n) //when it reaches at the end
      return left_sum == right_sum;
   if (arr[start] % 5 == 0) //when the element is divisible by 5, add to left sum
      left_sum += arr[start];
   else if (arr[start] % 3 == 0) //when the element is divisible by 3 but not 5, add to right sum
         right_sum += arr[start];
   else // otherwise it can be added to any of the sub-arrays
         return isSplitArray(arr, n, start + 1, left_sum + arr[start], right_sum) || isSplitArray(arr, n, start + 1, left_sum, right_sum + arr[start]);
   // For cases when element is multiple of 3 or 5.
   return isSplitArray(arr, n, start + 1, left_sum, right_sum);
}
int main() {
   int arr[] = {1, 4, 3};
   int n = sizeof(arr)/sizeof(arr[0]);
   if(isSplitArray(arr, n, 0, 0, 0)){
      cout <<"Can be split";
   } else {
      cout <<"Can not be split";
   }
}