Sub vectors

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

using namespace std;

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);
    }

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/


    //THE SUBARRAY WITH THE MAXIMUM SUM ⏩
    int sum = 0, ans = INT_MIN, st, en;
    for (int i = 0; i < n; i++) {
        for (int j = i; j < n; j++) {
            for (int k = i; k <= j; k++) {
                cout << v.at(k) << " ";
                sum += v.at(k);
            }
            cout << "   ";
            cout << sum << endl;
            if /*(max(sum, ans)==sum)*/ (sum > ans) {
                ans = sum;
                st = i;
                en = j;
            }

            sum = 0;
        }
        cout << endl;
    }

    cout << "The maximum sum of a subarray is: " << ans << " as the sum of subarray: " << st << " - " << en << endl;
    //<==THE SUBARRAY WITH THE MAXIMUM SUM


    /*

    //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 > ans) { //or ans=max(ans, sum);
            ans = sum;
        }
        if(sum<0) {
            sum=0;
        }

    }

    cout<<ans;

    */


/*
//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);
        sum = max(sum, 0);  //to check for -ve numbers ⏩ if the sum is -ve make (sum=0).
    }
    cout << ans;

    //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)").
*/




/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/


//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
*/


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



    return 0;

}