帮我用C++实现一个图书管理系统，运用C++语言描述书籍类、图书类型类、图书类，每一个类应包含数据成员和成员函数。设计基类和派生类，并运用多态性和虚函数的知识。

好的，下面是一个简单的图书管理系统的实现，包含书籍类、图书类型类、图书类以及基类和派生类的设计。

首先，我们需要设计三个类：书籍类、图书类型类和图书类。

1. 书籍类

书籍类包含以下数据成员：

- 书籍编号
- 书名
- 作者
- 出版社
- 出版日期

书籍类包含以下成员函数：

- 构造函数：用于初始化数据成员
- 获取书籍编号、书名、作者、出版社、出版日期的函数
- 设置书籍编号、书名、作者、出版社、出版日期的函数

class Book{
private:
    string bookID;
    string bookName;
    string author;
    string publisher;
    string publishDate;
public:
    Book(string id, string name, string author, string publisher, string date);
    string getBookID();
    string getBookName();
    string getAuthor();
    string getPublisher();
    string getPublishDate();
    void setBookID(string id);
    void setBookName(string name);
    void setAuthor(string author);
    void setPublisher(string publisher);
    void setPublishDate(string date);
};

Book::Book(string id, string name, string author, string publisher, string date){
    bookID = id;
    bookName = name;
    this->author = author;
    this->publisher = publisher;
    publishDate = date;
}

string Book::getBookID(){
    return bookID;
}
string Book::getBookName(){
    return bookName;
}
string Book::getAuthor(){
    return author;
}
string Book::getPublisher(){
    return publisher;
}
string Book::getPublishDate(){
    return publishDate;
}
void Book::setBookID(string id){
    bookID = id;
}
void Book::setBookName(string name){
    bookName = name;
}
void Book::setAuthor(string author){
    this->author = author;
}
void Book::setPublisher(string publisher){
    this->publisher = publisher;
}
void Book::setPublishDate(string date){
    publishDate = date;
}

2. 图书类型类

图书类型类包含以下数据成员：

- 图书类型编号
- 图书类型名称

图书类型类包含以下成员函数：

- 构造函数：用于初始化数据成员
- 获取图书类型编号、图书类型名称的函数
- 设置图书类型编号、图书类型名称的函数

class BookType{
private:
    string typeID;
    string typeName;
public:
    BookType(string id, string name);
    string getTypeID();
    string getTypeName();
    void setTypeID(string id);
    void setTypeName(string name);
};

BookType::BookType(string id, string name){
    typeID = id;
    typeName = name;
}

string BookType::getTypeID(){
    return typeID;
}
string BookType::getTypeName(){
    return typeName;
}
void BookType::setTypeID(string id){
    typeID = id;
}
void BookType::setTypeName(string name){
    typeName = name;
}

3. 图书类

图书类包含以下数据成员：

- 书籍类对象
- 图书类型类对象
- 借出日期
- 借出状态

图书类包含以下成员函数：

- 构造函数：用于初始化数据成员
- 获取书籍类对象、图书类型类对象、借出日期、借出状态的函数
- 设置借出日期、借出状态的函数

class BookItem{
private:
    Book book;
    BookType bookType;
    string borrowedDate;
    string borrowedStatus;
public:
    BookItem(Book book, BookType bookType);
    Book getBook();
    BookType getBookType();
    string getBorrowedDate();
    string getBorrowedStatus();
    void setBorrowedDate(string date);
    void setBorrowedStatus(string status);
};

BookItem::BookItem(Book book, BookType bookType){
    this->book = book;
    this->bookType = bookType;
}

Book BookItem::getBook(){
    return book;
}
BookType BookItem::getBookType(){
    return bookType;
}
string BookItem::getBorrowedDate(){
    return borrowedDate;
}
string BookItem::getBorrowedStatus(){
    return borrowedStatus;
}
void BookItem::setBorrowedDate(string date){
    borrowedDate = date;
}
void BookItem::setBorrowedStatus(string status){
    borrowedStatus = status;
}

接下来，我们需要设计基类和派生类，并运用多态性和虚函数的知识。

基类是一个抽象类，包含以下纯虚函数：

- 添加函数：用于添加书籍、图书类型、图书信息
- 修改函数：用于修改书籍、图书类型、图书信息
- 删除函数：用于删除书籍、图书类型、图书信息
- 查找函数：用于查找书籍、图书类型、图书信息
- 输出函数：用于输出书籍、图书类型、图书信息
- 排序函数：用于对图书信息按编号、书名排序
- 保存函数：用于将图书信息保存为文件

class LibrarySystem {
public:
    virtual void addBook(Book book) = 0;
    virtual void addBookType(BookType bookType) = 0;
    virtual void addBookItem(BookItem bookItem) = 0;
    virtual void modifyBook(Book book) = 0;
    virtual void modifyBookType(BookType bookType) = 0;
    virtual void modifyBookItem(BookItem bookItem) = 0;
    virtual void deleteBook(string bookID) = 0;
    virtual void deleteBookType(string typeID) = 0;
    virtual void deleteBookItem(string bookID) = 0;
    virtual void searchBook(string keyword) = 0;
    virtual void searchBookType(string keyword) = 0;
    virtual void searchBookItem(string keyword) = 0;
    virtual void sortBookItemByID() = 0;
    virtual void sortBookItemByName() = 0;
    virtual void saveToFile() = 0;
};

派生类是实际的类，继承基类并实现基类的纯虚函数。

例如，派生类可以是图书管理类，包含以下成员函数：

- 添加函数：用于添加书籍、图书类型、图书信息
- 修改函数：用于修改书籍、图书类型、图书信息
- 删除函数：用于删除书籍、图书类型、图书信息
- 查找函数：用于查找书籍、图书类型、图书信息
- 输出函数：用于输出书籍、图书类型、图书信息
- 排序函数：用于对图书信息按编号、书名排序
- 保存函数：用于将图书信息保存为文件

class BookManagement : public LibrarySystem {
private:
    vector<Book> books;
    vector<BookType> bookTypes;
    vector<BookItem> bookItems;
public:
    void addBook(Book book);
    void addBookType(BookType bookType);
    void addBookItem(BookItem bookItem);
    void modifyBook(Book book);
    void modifyBookType(BookType bookType);
    void modifyBookItem(BookItem bookItem);
    void deleteBook(string bookID);
    void deleteBookType(string typeID);
    void deleteBookItem(string bookID);
    void searchBook(string keyword);
    void searchBookType(string keyword);
    void searchBookItem(string keyword);
    void sortBookItemByID();
    void sortBookItemByName();
    void saveToFile();
};

void BookManagement::addBook(Book book){
    books.push_back(book);
}

void BookManagement::addBookType(BookType bookType){
    bookTypes.push_back(bookType);
}

void BookManagement::addBookItem(BookItem bookItem){
    bookItems.push_back(bookItem);
}

void BookManagement::modifyBook(Book book){
    for(int i=0; i<books.size(); i++){
        if(books[i].getBookID() == book.getBookID()){
            books[i] = book;
            break;
        }
    }
}

void BookManagement::modifyBookType(BookType bookType){
    for(int i=0; i<bookTypes.size(); i++){
        if(bookTypes[i].getTypeID() == bookType.getTypeID()){
            bookTypes[i] = bookType;
            break;
        }
    }
}

void BookManagement::modifyBookItem(BookItem bookItem){
    for(int i=0; i<bookItems.size(); i++){
        if(bookItems[i].getBook().getBookID() == bookItem.getBook().getBookID()){
            bookItems[i] = bookItem;
            break;
        }
    }
}

void BookManagement::deleteBook(string bookID){
    for(int i=0; i<books.size(); i++){
        if(books[i].getBookID() == bookID){
            books.erase(books.begin() + i);
            break;
        }
    }
}

void BookManagement::deleteBookType(string typeID){
    for(int i=0; i<bookTypes.size(); i++){
        if(bookTypes[i].getTypeID() == typeID){
            bookTypes.erase(bookTypes.begin() + i);
            break;
        }
    }
}

void BookManagement::deleteBookItem(string bookID){
    for(int i=0; i<bookItems.size(); i++){
        if(bookItems[i].getBook().getBookID() == bookID){
            bookItems.erase(bookItems.begin() + i);
            break;
        }
    }
}

void BookManagement::searchBook(string keyword){
    cout << "Search result for books:" << endl;
    for(int i=0; i<books.size(); i++){
        if(books[i].getBookID().find(keyword) != string::npos ||
           books[i].getBookName().find(keyword) != string::npos ||
           books[i].getAuthor().find(keyword) != string::npos ||
           books[i].getPublisher().find(keyword) != string::npos ||
           books[i].getPublishDate().find(keyword) != string::npos){
            cout << books[i].getBookID() << " " << books[i].getBookName() << " " << books[i].getAuthor() << " " << books[i].getPublisher() << " " << books[i].getPublishDate() << endl;
        }
    }
}

void BookManagement::searchBookType(string keyword){
    cout << "Search result for book types:" << endl;
    for(int i=0; i<bookTypes.size(); i++){
        if(bookTypes[i].getTypeID().find(keyword) != string::npos ||
           bookTypes[i].getTypeName().find(keyword) != string::npos){
            cout << bookTypes[i].getTypeID() << " " << bookTypes[i].getTypeName() << endl;
        }
    }
}

void BookManagement::searchBookItem(string keyword){
    cout << "Search result for book items:" << endl;
    for(int i=0; i<bookItems.size(); i++){
        if(bookItems[i].getBook().getBookID().find(keyword) != string::npos ||
           bookItems[i].getBook().getBookName().find(keyword) != string::npos ||
           bookItems[i].getBook().getAuthor().find(keyword) != string::npos ||
           bookItems[i].getBook().getPublisher().find(keyword) != string::npos ||
           bookItems[i].getBook().getPublishDate().find(keyword) != string::npos ||
           bookItems[i].getBookType().getTypeID().find(keyword) != string::npos ||
           bookItems[i].getBookType().getTypeName().find(keyword) != string::npos ||
           bookItems[i].getBorrowedDate().find(keyword) != string::npos ||
           bookItems[i].getBorrowedStatus().find(keyword) != string::npos){
            cout << bookItems[i].getBook().getBookID() << " " << bookItems[i].getBook().getBookName() << " " << bookItems[i].getBook().getAuthor() << " " << bookItems[i].getBook().getPublisher() << " " << bookItems[i].getBook().getPublishDate() << " " << bookItems[i].getBookType().getTypeID() << " " << bookItems[i].getBookType().getTypeName() << " " << bookItems[i].getBorrowedDate() << " " << bookItems[i].getBorrowedStatus() << endl;
        }
    }
}

void BookManagement::sortBookItemByID(){
    sort(bookItems.begin(), bookItems.end(), [](BookItem a, BookItem b){
        return a.getBook().getBookID() < b.getBook().getBookID();
    });
}

void BookManagement::sortBookItemByName(){
    sort(bookItems.begin(), bookItems.end(), [](BookItem a, BookItem b){
        return