Maximum Subarray Sum Excluding Certain Elements in C++

In this tutorial, we will be discussing a program to find maximum Subarray Sum Excluding Certain Elements.

For this we will be provided with two arrays of size M and N. Our task is to find a sub-array in the first array such that no element inside the subarray is present inside the second array and the elements of subarray sum up to be maximum.

Example

 Live Demo

#include <bits/stdc++.h>
using namespace std;
//checking if element is present in second array
bool isPresent(int B[], int m, int x) {
   for (int i = 0; i < m; i++)
   if (B[i] == x)
   return true;
   return false;
}
int findMaxSubarraySumUtil(int A[], int B[], int n, int m) {
   int max_so_far = INT_MIN, curr_max = 0;
   for (int i = 0; i < n; i++) {
      if (isPresent(B, m, A[i])) {
         curr_max = 0;
         continue;
      }
      curr_max = max(A[i], curr_max + A[i]);
      max_so_far = max(max_so_far, curr_max);
   }
   return max_so_far;
}
void findMaxSubarraySum(int A[], int B[], int n, int m) {
   int maxSubarraySum = findMaxSubarraySumUtil(A, B, n, m);
   if (maxSubarraySum == INT_MIN) {
      cout << "Maximum Subarray Sum cant be found" << endl;
   } else {
      cout << "The Maximum Subarray Sum = " << maxSubarraySum << endl;
   }
}
int main() {
   int A[] = { 3, 4, 5, -4, 6 };
   int B[] = { 1, 8, 5 };
   int n = sizeof(A) / sizeof(A[0]);
   int m = sizeof(B) / sizeof(B[0]);
   findMaxSubarraySum(A, B, n, m);
   return 0;
}

Output

The Maximum Subarray Sum = 7