Star pyramid

#include<iostream>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int length, left, right;
    length = 4 * n - 3;
    left = right = length / 2;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < length; j++)
        {
            if (j >= left && j <= right)
            {
                cout << "* ";
                j++;
            }
            cout << " ";
        }
        left -= 2;
        right += 2;
        cout << endl;
    }
    return 0;
}