Gunung samping

#include <iostream>
using namespace std;

int main() {
    int N;      // Kolom paling lebar
    int i,j;    //
    int diff=1; // you will know later

    cin >> N;

    for (i=1; i!=0; i+=diff) {
        for (j=0; j<i; j++) {
            cout << '*';
        }
        cout << endl;
        if (i==N)
            diff = -1;
    }


    return 0;
}