maximum subarray sum with positive and negative in cpp

How do you find the maximum sum of a Subarray?

How do you find the maximum subarray of an array?

maximum subarray sum brute force

maximum subarray sum with positive and negative number(O(n^3))

#include<bits/stdc++.h>

using namespace std;

int main()

{

    int ans=0,sum; //because empty subarray sum is zero

    int i,j,k,n;

    cin>>n;

  int  a[n];

  for(i=0;i<n;i++) cin>>a[i];

    for(i=0;i<n;i++)

    {

        for(j=i;j<n;j++)

        {

            sum=0;

            for(k=i;k<=j;k++)

            {

                sum+=a[k];

            }

            ans=max(ans,sum);

        }

    }

    cout<<ans<<endl;

    return 0;

}