这是使用数组实现的循环队列，同样也可以用链表实现，但原理都是一样的，就不重新写一份了，简单实现了数据的取出插入

类定义

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//
// Created by Tianyi on 2022/1/6.
//

#ifndef DATA_STRUCT_CIRCULAR_QUEUE_CIRCULAR_QUEUE_H
#define DATA_STRUCT_CIRCULAR_QUEUE_CIRCULAR_QUEUE_H

#include <iostream>

using namespace std;

#endif //DATA_STRUCT_CIRCULAR_QUEUE_CIRCULAR_QUEUE_H

class CircularQueue {
private:
    int * data;
    int capacity;
    int count;
    int head;
    int tail;

public:
    explicit CircularQueue(int capacity);
    CircularQueue();
    [[nodiscard]] bool isFull() const;
    [[nodiscard]] bool isEmpty() const;
    void push(const int &);
    int peek() const;
    int pool();
    void show() const;
};

循环队列相关操作

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//
// Created by Tianyi on 2022/1/6.
//
#include "../header/queue_define.h"

CircularQueue::CircularQueue() : CircularQueue(20) {}

CircularQueue::CircularQueue(int capacity) {
    this->capacity = capacity;
    this->count = 0;
    this->head = 0;
    this->tail = 0;
    this->data = new int[capacity];
}

bool CircularQueue::isFull() const {
    return this->count == this->capacity && this->head == this->tail;
}

bool CircularQueue::isEmpty() const {
    return this->count == 0;
}

/**
 * 队列添加元素
 * @param value
 */
void CircularQueue::push(const int &value) {
    if (isFull()) {
        cout << "The queue is FULL" << endl;
        return;
    }

    this->data[this->tail] = value;
    this->tail = (this->tail + 1) % this->capacity;
    this->count++;
}

/**
 * 取出头部元素，并不删除
 * @return
 */
int CircularQueue::peek() const {
    return this->data[this->head];
}

int CircularQueue::pool() {
    if (isEmpty()) {
        cout << "The queue is EMPTY!!!" << endl;
        return -65535;
    }

    int pool = this->data[this->head];
    this->head = (this->head + 1) % this->capacity;
    this->count--;

    return pool;
}

void CircularQueue::show() const {
    int index = 1;
    cout << "index " << index << " -- value " << this->data[this->head] << endl;
    for (int i = this->head + 1; i != this->tail; i = (i + 1) % this->capacity, index++) {
        cout << "index " << index << " -- value " << this->data[i] << endl;
    }
}

测试代码

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#include "../header/queue_define.h"

int main() {
    auto q = new CircularQueue(5);
    for (int i = 1; i <= 5; i++) {
        q->push(i);
        q->show();
        cout << "==================" << endl;
    }

    q->push(11);
    cout << "==================" << endl;

    for (int i = 1; i <= 5; i++) {
        cout << "pop value " << q->pool() << endl;
        cout << "==================" << endl;
    }

    cout << "pop value " << q->pool() << endl;
    return 0;
}