题解 | 空心正方形图案

#include <stdio.h>
int main()
{
    int i = 0, j = 0, n = 0;
    while (scanf("%d", &n) != EOF)
    {

        for (i = 0; i < n; i++)
        {
            if (i == 0 || i == n - 1)
            {
                for (j = 0; j < n; j++)
                    printf("* ");
                printf("\n");
            }
            else {
                for (j = 0; j < n; j++)
                {
                    if (j == 0 || j == n - 1)
                        printf("* ");
                    else
                        printf("  ");
                }
                printf("\n");
            }
        }
    }
    return 0;
}