c++写 创建一个循环队列，初始长度为n 循环队列的入队操作 循环队列的出队操作操作 循环队列的取队头元素操作 求循环队列的长度操作 循环队列的遍历操作

以下是C++实现循环队列的基本操作的代码，包括初始化、入队、出队、取队头元素、遍历输出队列、求队列长度等：

#include <iostream>
using namespace std;

const int MAXSIZE = 100; // 循环队列的最大长度

class CircularQueue {
private:
    int front; // 队头指针
    int rear; // 队尾指针
    int data[MAXSIZE]; // 队列数组
public:
    CircularQueue(int n) { // 初始化队列
        front = rear = 0;
        for (int i = 0; i < n; i++) {
            data[i] = 0;
        }
    }
    bool isEmpty() { // 判断队列是否为空
        return front == rear;
    }
    bool isFull() { // 判断队列是否已满
        return (rear + 1) % MAXSIZE == front;
    }
    int length() { // 求队列长度
        return (rear - front + MAXSIZE) % MAXSIZE;
    }
    bool enqueue(int x) { // 入队操作
        if (isFull()) {
            return false;
        }
        data[rear] = x;
        rear = (rear + 1) % MAXSIZE;
        return true;
    }
    bool dequeue() { // 出队操作
        if (isEmpty()) {
            return false;        }
        front = (front + 1) % MAXSIZE;
        return true;
    }
    int getFront() { // 取队头元素操作
        if (isEmpty()) {
            return -1;
        }
        return data[front];
    }
    void traverse() { // 遍历输出队列
        if (isEmpty()) {
            cout << "The queue is empty." << endl;
            return;
        }
        cout << "The elements in the queue are: ";
        int i = front;
        while (i != rear) {
            cout << data[i] << " ";
            i = (i + 1) % MAXSIZE;
        }
        cout << endl;
    }
};

int main() {
    int n = 5; // 循环队列的初始长度为5
    CircularQueue q(n);
    q.enqueue(1);
    q.enqueue(2);
    q.enqueue(3);
    q.enqueue(4);
    q.enqueue(5);
    q.traverse(); // 输出：The elements in the queue are: 1 2 3 4 5
    q.dequeue();
    q.dequeue();
    q.traverse(); // 输出：The elements in the queue are: 3 4 5
    cout << "The front element is: " << q.getFront() << endl; // 输出：The front element is: 3
    cout << "The length of the queue is: " << q.length() << endl; // 输出：The length of the queue is: 3
    return 0;
}