题解 | #空心正方形图案#

 #include <stdio.h>
void print (int num)
{
    int a = 0;
    int b = 0;
    
    for(a = 0;a < num;a++)
    {
        for (b = 0;b < num ;b++)
        {
            if(a == 0|| a == num - 1||b == 0||b == num - 1)
            {
            printf("* ");
            }
            else
            {
            printf("  ");
            }
        
        }
        printf("\n");
        
    }
}
int main()
{
    int num = 0;
    while (scanf("%d ",&num)!=EOF)
    {
    print(num);
    }
    return 0;
}