题解 | #空心正方形图案#

void print(int num)
{
    int i,j;
    for(i = 0; i < num; i++)
    {
        for(j = 0; j < num; j++)
        {
            if(i == 0 || i == num - 1 || j == 0 || j == num -1)
            {
                printf("* ");
            }
            else 
            {
                printf("  ");
            }
        }
        printf("\n");
    }
}

int main()
{
    int num;
    while(scanf("%d",&num) != EOF)
    {
        print(num);
    }
    return 0;
}