双向链表实现图书管理系统

双向链表可以用来实现图书管理系统中的书籍列表。每个节点可以表示一本书，节点中存储该书的相关信息，并且可以通过前后指针实现节点之间的链接。

以下是一个简单的双向链表实现：

#include <iostream>
#include <string>

using namespace std;

// 书籍信息结构体
struct Book {
    string title;
    string author;
    int year;
};

// 链表节点结构体
struct Node {
    Book data;
    Node* prev;
    Node* next;
};

// 链表类
class BookList {
public:
    BookList() : head(nullptr), tail(nullptr), size(0) {}
    ~BookList() {}

    // 添加一本书
    void addBook(Book book) {
        Node* newNode = new Node();
        newNode->data = book;
        newNode->prev = tail;
        newNode->next = nullptr;

        if (tail) {
            tail->next = newNode;
        }
        tail = newNode;

        if (!head) {
            head = newNode;
        }

        size++;
    }

    // 删除一本书
    void removeBook(string title) {
        Node* curr = head;
        while (curr) {
            if (curr->data.title == title) {
                if (curr->prev) {
                    curr->prev->next = curr->next;
                } else {
                    head = curr->next;
                }

                if (curr->next) {
                    curr->next->prev = curr->prev;
                } else {
                    tail = curr->prev;
                }

                delete curr;
                size--;
                return;
            }

            curr = curr->next;
        }
    }

    // 显示所有书籍
    void displayBooks() {
        Node* curr = head;
        while (curr) {
            cout << curr->data.title << " by " << curr->data.author << " (" << curr->data.year << ")" << endl;
            curr = curr->next;
        }
    }

private:
    Node* head;
    Node* tail;
    int size;
};

使用示例：

int main() {
    BookList bookList;

    bookList.addBook({"The Catcher in the Rye", "J.D. Salinger", 1951});
    bookList.addBook({"To Kill a Mockingbird", "Harper Lee", 1960});
    bookList.addBook({"1984", "George Orwell", 1949});

    bookList.displayBooks();

    bookList.removeBook("To Kill a Mockingbird");

    bookList.displayBooks();

    return 0;
}

输出：

The Catcher in the Rye by J.D. Salinger (1951)
To Kill a Mockingbird by Harper Lee (1960)
1984 by George Orwell (1949)

The Catcher in the Rye by J.D. Salinger (1951)
1984 by George Orwell (1949)