KADANE's ALGORITHM

C++

#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>

using namespace std;

int main() {

    int n;
    cin >> n;

    vector<int> v(n);

    for (int i = 0; i < n; i++) {
        cin >> v.at(i);
    }

/*BEST IMPLEMENTATION OF KADEN's ALGORITHM to solve
"SUBARRAY WITH THE MAXIMUM SUM or "MAXIMUM CONTAGIOUS SUBARRAY": */
    int sum = 0, ans = INT_MIN;
    for (int i = 0; i < n; i++) {
        sum += v.at(i);
        ans = max(ans, sum); //always assign it before max(sum, 0).
        sum = max(sum, 0);
    }
    cout << ans << "\n";
    //It prints the MAXIMUM SUBARRAY SUM or
    //IF ALL THE ELEMENTS ARE -ve, then it prints ONLY THE MAXIMUM -ve NUMBER (only if the the "max(sum, ans)" is applied before "max(sum, 0)").




//ALSO
    /*

    //KADEN's ALGORITHM to solve SUBARRAY WITH THE MAXIMUM SUM or "MAXIMUM CONTAGIOUS SUBARRAY"
    int sum = 0, ans = INT_MIN;
    for (int i = 0; i < n; i++) {
        sum += v.at(i);
        if(sum<0) {
            sum=0;
        }
        if (sum > ans) { //or ans=max(ans, sum);
            ans = sum;
        }
    }

    cout<<ans;

    */


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//KAADANE's ALGORITHM for "( MAXIMUM SUM OF CIRCULAR SUBARRAY )" ⏩
/*

#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>

using namespace std;

int kadane(vector<int> v) {
    int sum = 0, ans = INT_MIN;
    for (int i = 0; i < v.size(); i++) {
        sum += v.at(i);
        ans = max(ans, sum);
        sum = (sum, 0);
    }
    return ans;
}

int main() {

    freopen("inputf.in", "r", stdin);
    freopen("outputf.in", "w", stdout);

    int n;
    cin >> n;

    vector<int> v(n);

    for (int i = 0; i < n; i++)  {
        cin >> v.at(i);

    }

    int nonwrap = kadane(v);

    int wrap;
    int total = 0;
    for (int i = 0; i < n; i++) {
        total += v.at(i);
        v.at(i) = -v.at(i); //This will find the sum of the "non-wrapping SubArray which is to be removed."
    }

    wrap=total-(-kadane(v)); //as vector(v) has been made -ve, So " [-(sum of -ve vector(v))] ".

    cout << max(wrap, nonwrap);

    return 0;

}
//<==Ending of MAXIMUM SUM OF CIRCULAR SUBARRAY
*/

        /*###################################*/
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        /*###################################*/


/* //Using (Range For Loop) also called (For-each Loop) instead of for loop⏩
    int sum=0, ans=INT_MIN;
    for (auto el:v) {
        sum+= el;
        ans=max(ans,sum);
        sum=max(sum,0);
    }
    cout<<ans<<"\n";
*/

    return 0;
}

Java

class HelloWorld {
  public static void main(String args[]) {
    System.out.println("Hello, World");
  }
}

Python

def hello_world():
  print 'Hello, world!'