C++中队列的链接实现

#include <iostream>

// 定义链表节点
struct Node {
    int data;
    Node* next;
};

// 定义队列类
class Queue {
private:
    Node* front; // 队首指针
    Node* rear; // 队尾指针

public:
    // 构造函数
    Queue() {
        front = nullptr;
        rear = nullptr;
    }

    // 判断队列是否为空
    bool isEmpty() {
        return front == nullptr;
    }

    // 入队操作
    void enqueue(int value) {
        Node* newNode = new Node;
        newNode->data = value;
        newNode->next = nullptr;

        if (isEmpty()) {
            front = newNode;
            rear = newNode;
        } else {
            rear->next = newNode;
            rear = newNode;
        }
    }

    // 出队操作
    void dequeue() {
        if (isEmpty()) {
            std::cout << "队列为空，无法出队" << std::endl;
        } else {
            Node* temp = front;
            front = front->next;
            delete temp;
        }
    }

    // 获取队首元素
    int getFront() {
        if (isEmpty()) {
            std::cout << "队列为空" << std::endl;
            return -1;
        } else {
            return front->data;
        }
    }

    // 获取队列长度
    int getSize() {
        int count = 0;
        Node* current = front;
        while (current != nullptr) {
            count++;
            current = current->next;
        }
        return count;
    }
};

int main() {
    Queue queue;

    // 入队操作
    queue.enqueue(10);
    queue.enqueue(20);
    queue.enqueue(30);

    // 出队操作
    queue.dequeue();

    // 获取队首元素
    std::cout << "队首元素为：" << queue.getFront() << std::endl;

    // 获取队列长度
    std::cout << "队列长度为：" << queue.getSize() << std::endl;

    return 0;
}