题解 | #空心正方形图案#

#include<stdio.h>
int main()
{
    int a;
    while(~scanf("%d",&a))
    {
        int i,j;
        for(i=0;i<a;i++)
        {
            for(j=0;j<a;j++)
            {
                if(i==0)    
                {
                    printf("* ");
                }
                else if(i==a-1)
                {
                    printf("* ");
                }
                else if(j==0)
                {
                    printf("* ");
                }
                else if(j==a-1)
                {
                    printf("* ");
                }
                else
                {
                    printf("  ");
                }
            }
            printf("\n");
        }
    }
    return 0;
}