用带头结点的循环链表表示队列，并且只设一个指针指向队尾元素结点（不设头指针）。实现该队列的入队出队以及判断队列是否为空操作代码

很高兴能与您进行对话。以下是您所需要的代码实现：

#include <iostream>
using namespace std;

struct Node {
    int val;
    Node *next;
};

class Queue {
public:
    Queue() {
        rear = new Node;
        rear->next = rear; // 指向自己，表示队列为空
    }

    void add(int val) {
        Node *newNode = new Node;
        newNode->val = val;
        newNode->next = rear->next;
        rear->next = newNode;
        rear = newNode;
    }

    void remove() {
        if (rear == rear->next) {
            // 队列为空
            cout << "Queue is empty!" << endl;
            return;
        }
        Node *temp = rear->next->next;
        delete rear->next;
        rear->next = temp;
    }

    bool isEmpty() {
        return rear == rear->next;
    }

private:
    Node *rear;
};

int main() {
    Queue q;
    q.remove(); // 应输出：Queue is empty!
    q.add(1);
    q.add(2);
    q.add(3);
    while (!q.isEmpty()) {
        cout << "current front: " << q.front() << endl;
        q.remove();
    }
    // 应输出：
    // current front: 1
    // current front: 2
    // current front: 3
    // Queue is empty!
    return 0;
}

希望这个答案能够解决您的问题。