以下是代码：
#include<stdio.h>
int main(void)
{
    const unsigned int MIN_SIZE=3;
    unsigned int width=0;
    unsigned int height=0;
    printf("enter values for the width and height (minimum of %u):",MIN_SIZE);
    scanf_s("%u%u",&width,&height);
    if(width < MIN_SIZE)
    {
        printf("\nwidth value of %u is too small. setting it to %u.",width,MIN_SIZE);
        width=MIN_SIZE;
    }
    if(height < MIN_SIZE)
    {
        printf("\nwidth value of %u is too small. setting it to %u.",height,MIN_SIZE);
        height=MIN_SIZE;
    }
    for(unsigned int i=0 ; i<width ; ++i)
    {
        printf("*");

   
    for(unsigned int j=0 ; j<height-2 ; ++j)
   
        printf("\n*");


        for(unsigned int i=0 ; i<width-2 ; ++i)
            printf(" ");
        
        printf("*");

    }

    printf("\n");
    for(unsigned int i=0 ; i<width ; ++i)
   
        printf("*");
   

    printf("\n");
    return 0;
}
报错：
PS: 以上代码在VS2012能通过编译； 代码照书上的做一个箱子看看，可是不行啊！！

就是在开头声明i和j吗？

好吧，我都试试看