为啥下面的代码在scanf进行输入的时候会程序崩溃

为啥下面的代码在scanf进行输入的时候会程序崩溃，and有给我下面代码的一些建议吗，自我感觉写的不是很好，有很多地方都复杂化了，但不知道如何优化

完整代码：
Library.h

#pragma once
#define _CRT_SECURE_NO_WARNINGS
#define MAX 100
#include<stdio.h>
#include<stdlib.h>
#include<String.h>
#include<time.h>
//struct comment;
//struct book;
typedef struct student1//定义学生账号结构体
{
    int account;//账号
    char password[MAX];//密码
    char name[MAX];//姓名
    char student_number[MAX];//学号
    //int num;//借书数量
    //Book book[10];//借的书，并且最多只能借10本
};

typedef struct
{
    struct student1 student;
    char data[MAX];
    time_t timep;
    char time[MAX];
}Comment;

typedef struct book//定义书结构体
{
    char name[MAX];//书名
    char number[MAX];//书的编号
    double price;//书的价格
    int num;//书的数量
    Comment comment[MAX];
    int num_comment;//评论的数量
    struct student1 student[MAX];
    int num_student;
}Book;


typedef struct
{
    Book book[MAX];
    int num_book;
    struct student1 student;
    int num_student;
    Comment comment[MAX];
    int num_commnet;
}Student;

typedef struct Node//定义书链表
{
    Book data;
    struct Node* next;
}LinkList_book;

typedef struct Node1//定义学生账户链表
{
    Student data;
    struct Node1* next;
}LinkList_student;


//全局变量
//LinkList_book* L_book;//书链表
//LinkList_student* L_student;//学生账户链表

void CreateList_book();
void CreateList_student();

void welcome();

void Librarian();

void User();

void insert_book(Book book);
void insert_student(Student student);

LinkList_student* Find_student(int account);
LinkList_book* Find_book(char name[]);
Book Find_comment(char comment[]);//查找评论所在的书籍

void DispBook(LinkList_book* book);//单本
void Disp_Book();//所有


int Delete_book(char name[]);
int Delete_student(char name[]);

void Sort_book();

void saveInfoToFile_book(const char* FileName);
void saveInfoToFile_student(const char* FileName);
void readInfoToFile_book(const char* FileName);
void readInfoToFile_student(const char* FileName);

void DispComment_book(Book book);
void DispComment_student(Student student);

Library.cpp:

#include"Library.h"
extern LinkList_book* L_book;
extern LinkList_student* L_student;

void welcome()
{
    printf("------  图书管理系统  -----------\n");
    printf("******  1.管理员身份   **********\n");
    printf("******  2.用户身份     **********\n");
    printf("******  0.退出程序     **********\n");
    printf("---------------------------------\n");
}

//创建链表
void CreateList_book()
{
    L_book = (LinkList_book*)malloc(sizeof(LinkList_book));
    L_book->next = NULL;
}
void CreateList_student()
{
    L_student = (LinkList_student*)malloc(sizeof(LinkList_student));
    L_student->next = NULL;
}

//链表的插入
void insert_book(Book book)
{
    LinkList_book* p = NULL;
    p = (LinkList_book*)malloc(sizeof(LinkList_book));
    //Book book = { name, book_number, price, num};//?
    //Book book;
    strcpy(p->data.name, book.name);
    strcpy(p->data.number, book.number);
    p->data.price = book.price;
    p->data.num = book.num;
    p->data.num_comment = 0;
    p->data.num_student = 0;
    //p->data = book;
    LinkList_book* q = NULL;
    q = L_book;
    while (q->next != NULL)
    {
        q = q->next;
    }
    p->next = q->next;
    q->next = p;
}

void insert_student(Student student)
{
    LinkList_student* p = NULL;
    p = (LinkList_student*)malloc(sizeof(LinkList_student));
    //account = rand();//随机分配一个账户
   /* while (1)
    {
        account = rand();
        if (Find_student(account) == NULL)
        {
            break;
        }
    }*/
    //Student student = { temp_account, password, name, student_number, 0 };//?
    //Student student;
    p->data.student.account = student.student.account;
    strcpy(p->data.student.password, student.student.password);
    strcpy(p->data.student.name, student.student.name);
    strcpy(p->data.student.student_number, student.student.student_number);
    p->data.num_book = 0;
    p->data.num_commnet = 0;
    p->data.num_student = 0;
    //p->data = student;
    LinkList_student* q = NULL;
    q = L_student;
    while (q->next != NULL)
    {
        q = q->next;
    }
    p->next = q->next;
    q->next = p;
}

//根据账号查找
LinkList_student* Find_student(int account)
{
    LinkList_student* p = NULL;
    p = L_student->next;
    while (p != NULL)
    {
        if (p->data.student.account == account)
        {
            break;
        }
        p = p->next;
    }
    return p;
}
//根据图书名字查找
LinkList_book* Find_book(char name[])
{
    LinkList_book* p = NULL;
    p = L_book->next;
    while (p != NULL)
    {
        if (strcmp(p->data.name, name) == 0)
        {
            break;
        }
        p = p->next;
    }
    return p;
}

Book Find_comment(char comment[])//查找评论所在的书籍
{
    int i = 0;
    LinkList_book* p = NULL;
    p = L_book->next;
    while (p != NULL)
    {
        for (i = 0; i < p->data.num_comment; i++)
        {
            if (strcmp(p->data.comment[i].data, comment) == 0)
            {
                break;
            }
        }
        p = p->next;
    }
    return p->data;
}


//打印单本书
void DispBook(LinkList_book* book)
{
    char name[] = "书名";
    char number[] = "编号";
    char price[] = "价格";
    char num[] = "数量";
    printf("%-16s%-16s%-16s%s\n", name, number, price, num);
    printf("%-16s%-16s%-16f%-16d\n", book->data.name,
        book->data.number, book->data.price, book->data.num);
}

//打印所有图书
void Disp_Book()
{
    LinkList_book* temp_book = L_book->next;
    while (temp_book != NULL)
    {
        DispBook(temp_book);
        temp_book = temp_book->next;
    }
}

//删除书
int Delete_book(char name[])

{
    LinkList_book* p = NULL, * q = NULL;
    p = L_book;
    q = p->next;
    int flag = 0;
    while (q != NULL)
    {
        if (strcmp(q->data.name, name) == 0)
        {
            p->next = q->next;
            free(q);
            flag = 1;
            break;
        }
        p = p->next;
        q = p->next;
    }
    return flag;
}

//删除学生账号
int Delete_student(char name[])
{
    int flag = 0;
    LinkList_student* p = NULL, * q;
    q = p = L_student->next;
    while (p != NULL)
    {
        if (strcmp(p->data.student.name, name) == 0)
        {
            p->next = q->next;
            free(q);
            flag = 1;
            break;
        }
        p = p->next;
        q = p->next;
    }
    return flag;
}

//按照价格图书排序
void Sort_book()
{
    LinkList_book* temp_book = L_book;//复制单链表
    LinkList_book* p = NULL, * q = NULL, * r = NULL;//使用两个指针
    r = temp_book;
    while (p != NULL && q != NULL)
    {
        p = r->next;
        q = p->next;
        if (p->data.price > q->data.price)
        {
            p->next = q->next;
            q->next = p;
            r->next = q;
        }
        r = p;
        DispBook(r);
    }
}

//文件写操作
void saveInfoToFile_book(const char* FileName)//书
{
    FILE* pf = fopen(FileName, "w");
    LinkList_book* pMove = L_book->next;
    while (pMove != NULL)
    {
        //fwrite(&pMove, sizeof(Book), 1, pf);
        fwrite(&pMove->data, sizeof(Book), 1, pf);
        pMove = pMove->next;
    }
    fclose(pf);
    pf = NULL;
}

void saveInfoToFile_student(const char* FileName)
{
    FILE* pf = fopen(FileName, "w");
    LinkList_student* pMove = L_student->next;
    while (pMove != NULL)
    {
        //fwrite(&pMove, sizeof(Student), 1, pf);
        fwrite(&pMove->data, sizeof(Student), 1, pf);
        pMove = pMove->next;
    }
    fclose(pf);
    pf = NULL;
}
//文件读操作
void readInfoToFile_book(const char* FileName)
{
    FILE* pf = fopen(FileName, "r");
    if (pf == NULL)
    {
        pf = fopen(FileName, "w+");
    }
    //LinkList_book* pMove = NULL;
    Book book;
    //while (fread(&pMove, sizeof(Book), 1, pf) != 0)
    while (1)
    {
        /*pMove = (LinkList_book*)malloc(sizeof(LinkList_book));
        insert_book(pMove->data.name, pMove->data.number, pMove->data.price, pMove->data.num);*/
        if (fread(&book, sizeof(Book), 1, pf) != 1)
            break;
        insert_book(book);
    }
    fclose(pf);
    pf = NULL;
}

void readInfoToFile_student(const char* FileName)
{
    FILE* pf = fopen(FileName, "r");
    if (pf == NULL)
    {
        pf = fopen(FileName, "w+");
    }
    //LinkList_student* pMove = NULL;
    Student student1;
    //while (fread(&pMove, sizeof(Book), 1, pf) != 0)
    while (1)
    {
        /*pMove = (LinkList_student*)malloc(sizeof(LinkList_student));
        insert_student(pMove->data.password, pMove->data.name, pMove->data.student_number, pMove->data.account);*/
        if (fread(&student1, sizeof(Student), 1, pf) != 1)
            break;
        insert_student(student1);
    }
    fclose(pf);
    pf = NULL;
}

void DispComment_book(Book book)
{
    int i = 0;
    printf("========该书共有%d条评论=======\n");
    for (i = 0; i < book.num_comment; i++)
    {
        printf("%5s%s\n%s\n", book.comment[i].student.name, book.comment[i].time, book.comment[i].data);
    }
}

void DispComment_student(Student student)
{
    int i = 0;
    Book temp_book;
    for (i = 0; i < student.num_commnet; i++)
    {
        temp_book = Find_comment(student.comment[i].data);
        printf("《%s》%s\n%s", temp_book.name, student.comment[i].time, student.comment[i].data);
    }
}

Libralian.cpp

#include"Library.h"
extern LinkList_book* L_book;
extern LinkList_student* L_student;
void LibrarianMenu()//管理员菜单
{
    printf("-------    管理员界面   ---------\n");
    printf("******  1.注册新图书   **********\n");
    printf("******  2.查看已存图书    *******\n");
    printf("******  3.修改已有图书    *******\n");
    printf("******  4.注销现存图书    *******\n");
    printf("******  0.返回上一层    *********\n");
    printf("---------------------------------\n");
}

void Librarian()
{
    int input = 0;
    int ret = 0;
    do
    {
        LibrarianMenu();
        printf("请输出0-4:>");
        scanf("%d", &input);
        LinkList_book* temp_book = NULL;//临时书本
        char temp_name[MAX];//临时书本名
        char temp_number[MAX];//临时书本编号
        double temp_price;//临时书本价格
        int temp_num;//临时书本数量
        int temp;//临时选项
        switch (input)
        {
        case 1:
            printf("--------【注册新图书】---------\n");
            printf("书名:>");
            scanf("%s", temp_book->data.name);
            printf("\n编号:>");
            scanf("%s", temp_book->data.number);
            printf("\n价格:>");
            scanf("%lf", &temp_book->data.price);
            printf("\n数量:>");
            scanf("%d", &temp_book->data.num);
            printf("\n");
            insert_book(temp_book->data);
            saveInfoToFile_book("book.txt");
            break;
        case 2:
            printf("--------【查看已存图书】---------\n");
            Disp_Book();
            break;
        case 3:
            printf("--------【修改已有图书】---------\n");
            printf("请输入需要修改书本的名字:>");
            scanf("%s", temp_name);
            printf("\n");
            temp_book = Find_book(temp_name);
            if (temp_book == NULL)
            {
                printf("该图书尚未注册\n");
            }
            else
            {
                printf("-----------------------\n");
                printf("********1.书名*********\n");
                printf("********2.编号*********\n");
                printf("********3.价格*********\n");
                printf("********4.数量*********\n");
                printf("请选择需要修改的选项:>");
                scanf("%d", &temp);
                switch (temp)
                {
                case 1:
                    printf("修改后的书名:>");
                    scanf("%s", temp_name);
                    strcpy(temp_book->data.name, temp_name);
                    break;
                case 2:
                    printf("修改后的编号:>");
                    scanf("%s", temp_number);
                    strcpy(temp_book->data.number, temp_number);
                    break;
                case 3:
                    printf("修改后的价格:>");
                    scanf("%lf", &temp_price);
                    temp_book->data.price = temp_price;
                    break;
                case 4:
                    printf("修改后的数量:>");
                    scanf("%lf", &temp_num);
                    temp_book->data.num = temp_num;
                    break;
                }
            }
            saveInfoToFile_book("book.txt");
            break;
        case 4:
            printf("--------【注销现存图书】---------\n");
            printf("请输入要删除的书名:>");
            scanf("%s", temp_name);
            ret = Delete_book(temp_name);
            if (ret == 1)
            {
                printf("-----删除成功《%s》-----\n", temp_name);
                saveInfoToFile_book("book.txt");
            }
            else
            {
                printf("-----删除失败-----\n");
            }
            break;
        case 0:
            printf("-----------返回上一层------------\n");
            input = 0;
            break;
        default:
            printf("输入有误，请输入0-4间的数字\n");
            break;
        }
    } while (input);
}

User.cpp:

#include"Library.h"
extern LinkList_book* L_book;
extern LinkList_student* L_student;

char temp_name[MAX];
Comment temp_comment;
LinkList_book* temp_book;
char choice = 0;//功能里的其他选择临时变量

void UserMenu()//用户菜单
{
    printf("------     用户界面    ----------\n");
    printf("******  1.登录         **********\n");
    printf("******  2.注册            *******\n");
    printf("******  0.返回上一层   **********\n");
    printf("---------------------------------\n");
}

void UserMenu2()
{
    printf("------     用户使用界面 ---------\n");
    printf("******  1.查找图书     **********\n");
    printf("******  2.查看已存图书    *******\n");
    printf("******  3.借阅图书        *******\n");
    printf("******  4.归还图书        *******\n");
    printf("******  5.按照价格图书排序*******\n");
    printf("******  6.写评论          *******\n");
    printf("******  7.查看我的评论    *******\n");
    printf("******  0.返回上一层   **********\n");
    printf("---------------------------------\n");
}

void seekBook()
{
    printf("--------【查找图书】---------\n");
    printf("请输入需要查找的图书名:>");
    scanf("%s", temp_name);
    temp_book = Find_book(temp_name);
    if (temp_book != NULL)
    {
        DispBook(temp_book);
    }
    else
    {
        printf("没有找到该图书\n");
    }
    printf("是否查看《%s》评论？y/n:>", temp_name);
    scanf("%c", &choice);
    if (choice == 'y')
    {
        printf("=========该书共有%d条评论=======\n");
        DispComment_book(temp_book->data);
    }
}

void Register(LinkList_student* student)
{
    int input;
    do
    {
        UserMenu2();
        printf("请输入0-5:>");
        scanf("%d", &input);
        switch (input)
        {
        case 1:
            seekBook();
            break;
        case 2:
            printf("--------【查看已存图书】---------\n");
            Disp_Book();
            break;
        case 3:
            printf("--------【借阅图书】---------\n");
            printf("请输入要借阅图书的名字:>");
            scanf("%s", temp_name);
            temp_book = Find_book(temp_name);
            if (temp_book != NULL)
            {
                student->data.book[student->data.num_book++] = temp_book->data;//学生借的书本数量+1
                temp_book->data.num--;//图书馆里书本数量少1
            }
            else
            {
                printf("该图书尚且还未注册\n");
            }
            saveInfoToFile_book("book.txt");
            break;
        case 4:
            printf("--------【归还图书】---------\n");
            printf("请输入要归还图书的名字:>");
            scanf("%s", temp_name);
            temp_book = Find_book(temp_name);
            if (temp_book != NULL)
            {
                student->data.num_book--;
                Delete_book(temp_name);
            }
            else
            {
                printf("您还未借过该本书\n");
            }
            saveInfoToFile_book("book.txt");
            break;
        case 5:
            printf("--------【按照价格图书排序】---------\n");
            Sort_book();
            break;
        case 6:
            printf("--------【评论】---------\n");
            printf("请输入需要评论的书籍:>");
            scanf("%s", temp_name);
            temp_book = Find_book(temp_name);
            if (temp_book != NULL)
            {
                printf("请输入你的评论:>");
                scanf("%s", temp_comment.data);
                time(&temp_comment.timep);
                strcpy(temp_comment.time,asctime(gmtime(&temp_comment.timep)));//字符串复制用strcpy
                temp_book->data.comment[temp_book->data.num_comment++] = temp_comment;
                printf("====成功写入评论====\n");
            }
            else
            {
                printf("==========该书尚未注册=======\n");
            }
            break;
        case 7:
            printf("--------【查看我的评论 】---------\n");
            printf("======我共有%d条评论========\n", student->data.num_commnet);
            DispComment_student(student->data);
            break;
        case 0:
            printf("-----------返回上一层------------\n");
            input = 0;
            break;
        default:
            printf("输入有误，请输入0-5间的数字\n");
            break;
        }
    } while (input);
}

void User()
{
    int input;
    int account;
    LinkList_student* temp = NULL;//
    do
    {
        UserMenu();
        printf("请输入0-2:>");
        scanf("%d", &input);
        switch (input)
        {
            //{
        case 1://登录
            //LinkList_student * temp = NULL;//
            int account;//储存用户的账号
            char password[MAX];//储存用户的密码
            printf("--------【登录界面】---------\n");
            printf("请输入账号和密码：\n");
            printf("账号:>");
            scanf("%d", &account);
            temp = Find_student(account);
            if (temp == NULL)//未找到该账户
            {
                char ret = 0;
                printf("该用户不存在，是否注册，不注册则返回上一层：y/n:>");
                scanf(" %c", &ret);/////////////////////////////////////////
                if (ret == 'n')
                {
                    break;
                }
                printf("\n");
            }
            else//找到了
            {
                while (1)
                {
                    printf("密码:>");
                    scanf("%s", password);
                    if (strcmp(password, temp->data.student.password) == 0)
                    {
                        printf("============登录成功==============\n");
                        Register(temp);
                        break;
                    }
                    else
                    {
                        printf("\n密码错误，请重新输入:>\n");
                    }
                }
                break;
            }
            //}
        case 2:
            printf("--------【注册界面】---------\n");
            while (1)
            {
                account = rand();
                if (Find_student(account) == NULL)
                {
                    break;
                }
            }
            //char temp_password[MAX];
            printf("请设置密码:>");
            scanf("%s", temp->data.student.password);
            //char temp_name[MAX];
            printf("\n请输入姓名:>");
            scanf("%s", temp->data.student.name);
            //char temp_student_number[MAX];
            printf("\n请输入学号:>");
            scanf("%s", temp->data.student.student_number);
            insert_student(temp->data);
            printf("\n注册成功，你的账号为：%d\n", account);
            saveInfoToFile_student("student.txt");
            break;
        case 0:
            printf("-----------返回上一层------------\n");
            input = 0;
            break;
        default:
            printf("输入有误，请输入0-2间的数字\n");
            break;
        }
    } while (input);
}

test.cpp

#include"Library.h"
LinkList_book* L_book;
LinkList_student* L_student;
int main()
{
    CreateList_book();
    CreateList_student();
    readInfoToFile_book("book.txt");
    readInfoToFile_student("student.txt");
    srand((unsigned int)time(NULL));
    int input = 0;// 控制用户的输入的变量
    do
    {
        welcome();//进入菜单
        printf("请选择0-2:>");
        scanf("%d", &input);//用户选择
        switch (input)
        {
        case 1://选择管理员
            Librarian();//进入管理员界面
            break;
        case 2://选择用户
            User();//进入用户界面
            break;
        case 0:
            printf("退出程序\n");
            break;
        default:
            printf("输入有误，请输入0-2间的数字\n");
            break;
        }
        //system("cls");
    } while (input);//输入为0自动退出
    return 0;
}

LinkList_book* temp_book = NULL; 这个空指针没有分配空间啊，后面scanf自然就崩溃了