struct Books_list { int id; //书号 char name[30]; //书名 char author[30]; //作者 char press[30]; //出版社名 }; struct Books_list book1[MAX_BOOKS]={ {1,"唐诗三百首","孙洙","南京大学出版社"}, {2,"三体","刘慈欢","北美权威科幻类出版社"}, {3,"稻草人","叶圣陶","湖南儿童出版社"}, {4,"老人与海","海明威","上海译文出版社"}, {5,"c语言","泰戈尔","浙江文艺出版社"}, };void addbook(struct Books_list book1) { struct Books_list BOOK; printf("序号："); scanf("%s",BOOK.id); printf("书名："); scanf("%s",BOOK.name); printf("作者："); scanf("%s",BOOK.author); printf("出版社："); scanf("%s",BOOK.press); book1[count++]=BOOK; printf("添加成功！\n"); }怎么修改这段代码

这段代码存在以下问题：

1. scanf("%s",BOOK.id)应该改为scanf("%d",&BOOK.id)，因为id是整型，需要用%d进行格式化输入。

2. count变量没有定义，需要在函数外部定义一个全局变量int count=5;来记录已有的书籍数量。

3. addbook()函数中的book1是一个数组名，不能作为参数传递，否则会退化为指针类型。正确的写法应该是传递一个Books_list类型的结构体参数，例如：void addbook(struct Books_list newbook)。

修改后的代码如下：

#define MAX_BOOKS 100

struct Books_list {
    int id;           //书号
    char name[30];    //书名
    char author[30];  //作者
    char press[30];   //出版社名
};

struct Books_list book1[MAX_BOOKS] = {
    {1, "唐诗三百首", "孙洙", "南京大学出版社"},
    {2, "三体", "刘慈欢", "北美权威科幻类出版社"},
    {3, "稻草人", "叶圣陶", "湖南儿童出版社"},
    {4, "老人与海", "海明威", "上海译文出版社"},
    {5, "c语言", "泰戈尔", "浙江文艺出版社"}
};

int count = 5;

void addbook(struct Books_list newbook) {
    printf("序号：");
    scanf("%d", &newbook.id);
    printf("书名：");
    scanf("%s", newbook.name);
    printf("作者：");
    scanf("%s", newbook.author);
    printf("出版社：");
    scanf("%s", newbook.press);
    book1[count++] = newbook;
    printf("添加成功！\n");
}