题解 | #空心正方形图案#

#include <stdio.h>

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

    return 0;
}