题解 | #空心正方形图案#

#include <iostream>

using namespace std;

int main()
{
    int n;
    while (cin >> n)
    {
        for (int i = 0; i < n; i++)
        {
            if (i == 0 || i == n - 1)
            {
                for (int j = 0; j < n; j++)
                {
                    cout << "* ";
                }
                cout << endl;
            }
            else
            {
                for (int j = 0; j < n; j++)
                {
                    if (j == 0 || j == n -1)
                    {
                        cout << "* ";
                    }
                    else
                    {
                        cout << "  ";
                    }
                }
                cout << endl;
            }
        }
    }
    return 0;
}