c语言写了个图书管理代码，选项为1.2.3的时候运行bug，核对好多遍了，哪里出错了？

Question

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
              
int booknum=0;
struct TIME{
    int year;
    int month;
    int day;
};
struct BOOK{
    char name[250];
    struct TIME time;
    char cbs[250];    
}*book=NULL;//定义book指针并赋值为空

void inquire(struct BOOK *book,int booknum);//查询书籍
void add(struct BOOK *book,int booknum);//添加书籍
void delet(struct BOOK *book);//删除书籍
void print(struct BOOK *book,int i);//打印书籍
void select();//菜单选项
void printall(struct BOOK *book); //打印所有书籍信息

void delet(struct BOOK *book)
{ 
    char ch[25];
    printf("请输入书名：\n");
    scanf("%s",ch);
    for(int i=0;i<booknum;i++)
    {
        if(strcmp(book[i].name,ch)==0)
        {
        strcpy(book[i].name,book[i+1].name);
        book->time.year=0; book->time.month=0; book->time.day=0;
        strcpy(book[i].cbs,book[i+1].cbs);
        booknum--;
        }
    }
}

void inquire(struct BOOK *book,int booknum)//查询书籍 
{    
    char ch;    
    while((ch=getchar())!='p')
    {    
    char ch[25];
    printf("请输入查询的书名：\n");
    scanf("%s",ch);
    for(int i=0;i<booknum;i++)
        {
            if(strcmp(book[i].name,ch)==0)
            {
             printf("\t此书编号\t\t书名\t\t出版日期\t\t出版社\t\n\n");
             print(&book[i],i);//传参到输出函数print
             //break;                     
            }
            else printf("查无此书！\n");break;
        }
    printf("输入p停止查询,否则继续查询...\n");        
    }
    select();    
}

void add(struct BOOK *book,int booknum)//添加书籍 
{    
    char ch;
    while((ch=getchar())!='p')
    {
    booknum++;
    printf("这是第%d本书\n",booknum);
    printf("请输入书名：\n");
    scanf("%s",book->name); 
    printf("请输入出版日期(年月日)：\n");
    scanf("%d%d%d",&(book->time.year),&(book->time.month),&(book->time.day)); 
    printf("请输入出版社：\n");
    scanf("%s",book->cbs);
    printf("====添加完成！====\n");
    printf("输入p停止添加\n");    
    }
    select();      
}

void print(struct BOOK *book,int i)
{
printf("\t%d\t\t%s\t\t",i,book->name);
printf("%d-%d-%d",book->time.year,book->time.month,book->time.day);
printf("\t\t%s\t\n",book->cbs);
}

void select()//选择操作 
{  
    int code;
    printf("-----------------------------------------------------------------------------------------------------------------------\n\n");
    printf("\t\t\t1.录入书籍\t\t2.查询书籍\n\n\t\t\t3.删除书籍\t\t4.结束程序\t\t5.打印所有书籍信息\n\n");
    printf("-----------------------------------------------------------------------------------------------------------------------\n");
    printf("\t  请选择模式：");
    scanf("%d",&code);//输入非数字将陷入死循环 
    printf("\n\n"); 
    switch(code)
    {
        case 1:add(book,booknum);    break;
        case 2:inquire(book,booknum);break;
        case 3:delet(book);          break;
        case 4:exit(0);              break;
        case 5:printall(book);         break; 
        default:printf("请重新输入选项！！！\n");break;
    }
    select();    
}

void printall(struct BOOK *book)
{    
    printf("\t此书编号\t\t书名\t\t出版日期\t\t出版社\t\n\n");
    for(int j=0;j<booknum;j++)
    {
        print(&book[j],j);
    }
    printf("====所有书籍信息打印完毕！====\n");
    select();    
}

int main()
{    
    printf("请选择操作：\n");
    select();
    return 0;
}

Answer 1

修改完善如下，改动处见注释，供参考：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

int booknum = 0;
struct TIME {
    int year;
    int month;
    int day;
};
struct BOOK {
    char name[50];
    struct TIME time;
    char cbs[250];
}book[100]; //*book = NULL;//定义book指针并赋值为空  修改

//void inquire(struct BOOK* book, int booknum);//查询书籍  //修改
//void add(struct BOOK* book, int booknum);//添加书籍      //修改
//void delet(struct BOOK* book);//删除书籍
//void print(struct BOOK* book, int i);//打印书籍
//void select();//菜单选项
//void printall(struct BOOK* book); //打印所有书籍信息

void print(struct BOOK* book, int i)
{
    printf("\t%d\t%s\t", i, book->name);
    printf("%d-%d-%d", book->time.year, book->time.month, book->time.day);
    printf("\t%s\n", book->cbs);
}

void delet(struct BOOK* book)
{
    int  flg = 1;    //修改
    char ch[50];
    printf("请输入书名：\n");
    scanf("%s", ch);
    for (int i = 0; i < booknum; i++)
    {
        if (strcmp(book[i].name, ch) == 0)
        {
            for (int j = i; j < booknum - 1; j++) //修改
                book[j] = book[j + 1];            //修改
            //strcpy(book[i].name, book[i + 1].name);  //修改
            //book->time.year = 0; book->time.month = 0; book->time.day = 0;//修改
            //strcpy(book[i].cbs, book[i + 1].cbs);   //修改
            i--;                                //修改
            booknum--;                          //修改
            flg = 0;                            //修改
            printf("删除成功！\n");             //修改  
        }
    }
    if (flg)   //修改
        printf("未找到相关记录！\n");
}

void inquire(struct BOOK* book)//查询书籍  void inquire(struct BOOK* book, int booknum) 修改
{
    char ch;
    do{      //修改
        char name[50];  //char ch[25]; 修改
        printf("请输入查询的书名：\n");
        scanf("%s", name); // scanf("%s", ch); 修改
        for (int i = 0; i < booknum; i++)
        {
            if (strcmp(book[i].name, name) == 0)  //strcmp(book[i].name, ch
            {
                printf("\t此书编号\t书名\t出版日期\t出版社\n\n");
                print(&book[i], i);//传参到输出函数print
                break;                     
            }
            //else printf("查无此书！\n"); break;
            if (i == booknum - 1)       //修改
                printf("查无此书！\n"); 
        }
        printf("输入p停止查询,否则继续查询...\n");
        getchar();  //修改
    }while ((ch = getchar()) != 'p');   //修改
    //select();  修改
}



void add(struct BOOK* book)//添加书籍  修改  void add(struct BOOK* book, int booknum)
{
    int  i = booknum;      //修改 
    char ch;
    do{      //修改
        printf("这是第%d本书\n", i + 1);
        printf("请输入书名：\n");
        scanf("%s", book[i].name);
        printf("请输入出版日期(年月日)：\n");
        scanf("%d%d%d", &book[i].time.year, &book[i].time.month, &book[i].time.day);
        printf("请输入出版社：\n");
        scanf("%s", book[i].cbs);
        i++;
        printf("====添加完成！====\n");
        printf("输入p停止添加\n");
        getchar();                 //修改
    } while ((ch = getchar()) != 'p');//修改
    booknum = i;                  //修改
    //select(); //修改
}


void printall(struct BOOK* book)
{
    printf("\t此书编号\t书名\t出版日期\t出版社\n\n");
    for (int j = 0; j < booknum; j++)
    {
        print(&book[j], j);
    }
    printf("====所有书籍信息打印完毕！====\n");
    //select();  //修改
}

void select()//选择操作 
{
    int code;
    printf("-------------------------------------------------------------------------------------------\n\n"); //修改
    printf("\t\t\t1.录入书籍\t2.查询书籍\n\n\t\t\t3.删除书籍\t4.结束程序\n\n\t\t\t5.打印所有书籍信息\n\n");    //修改
    printf("-------------------------------------------------------------------------------------------\n");   //修改
    printf("\t  请选择模式：");
    scanf("%d", &code);//输入非数字将陷入死循环 
    printf("\n\n");
    switch (code)
    {
    case 1:add(book);    break;  //add(book, booknum); //修改
    case 2:inquire(book); break; //inquire(book, booknum);//修改
    case 3:delet(book);          break;
    case 4:exit(0);              break;
    case 5:printall(book);       break;
    default:printf("请重新输入选项！！！\n"); break;
    }
    select();
}

int main()
{
    printf("请选择操作：\n");
    select();
    return 0;
}