【数据结构】C++语言环形队列的实现

队列——先进先出

队列的一个缺点——出队后的内存空间浪费了，不能二次利用

环形队列——解决以上缺点的队列，用过的内存空间可以重复利用

github: https://github.com/HITFishily/CandCPP/blob/master/ring_queue.h

代码：

#include <iostream>

using namespace std;

template<typename T> class CircleQueue
{
private:
    unsigned int    m_size;
    int             m_front;
    int             m_rear;
    T*              m_data;
public:
    CircleQueue(unsigned int size)
    {
        m_front = 0;
        m_rear  = 0;
        m_size  = size + 1;
        m_data  = new T[m_size + 1];
    }
    ~CircleQueue()
    {
        delete[] m_data;
    }
    bool isEmpty()
    {
        return m_front == m_rear;
    }
    bool isFull()
    {
        return m_front == (m_rear + 1) % m_size;
    }
    void push(T data)
    {
        if (isFull())
        {
            throw "The queue is full，cannot keep pushing.";
        }
        m_data[m_rear] = data;
        m_rear = (m_rear + 1) % m_size;
    }
    void pop()
    {
        if (isEmpty())
        {
            throw new exception("The queue is empty，cannot keep poping.");
        }
        m_front = (m_front + 1) % m_size;
    }
    void popall()
    {
        if (isEmpty())
        {
            throw new exception("The queue is empty，cannot keep poping.");
        }
        while (m_front != m_rear)
            m_front = (m_front + 1) % m_size;
    }
    T top()
    {
        if (isEmpty())
        {
            throw new exception("The queue is empty，cannot access the top element.");
        }
        return m_data[m_front];
    }
};