# 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

Updated on: 10-Jul-2020

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