题解 | #空心正方形图案#

#include <stdio.h>

int main()
{
    int n = 0;
    while (scanf("%d",&n ) != EOF)
    {
        for (int i = 0;i < n;i++)
        {
            for (int j = 0;j < n;j++)
            {
                if (i == 0 || i == n-1 || j == 0 || j == n-1)
                {
                    printf("* ");
                }
                else 
                {
                    printf("  ");
                }
            }
            printf("\n");
        }
    }
    return 0;
}