задача 3

#include <iostream>
#include <fstream>
#include <cmath>
#include <math.h>


using namespace std;

int n;
int c = 1;

int main(int argc, const char * argv[]) {

    cin >> n;
    int b = n - 1;
    for (int i = 1 ; i <= n ; i++ ) {
        for(int j = 1 ; j <= b ; j++ ) {
            cout << " ";
        }
        for(int d = 1 ; d <= c ; d++ ) {
            cout << "*";
        }
        for(int j = 1 ; j < i ; j++ ) {
            cout << "*";
        }
        c = c + 1;
        b = b - 1;
        cout << endl;
    }
    int y = n-1;
    int g = 2;
    for (int i = n ; i >=1 ; i-- ) {
         for(int d = 1 ; d < g ; d++ ) {
            cout << " ";
        }
        for(int j = 1 ; j <= y ; j++ ) {
            cout << "*";
        }
        for(int j = 1 ; j < y ; j++ ) {
            cout << "*";
        }
        g = g + 1;
        y = y - 1;
        cout << endl;
    }
}