数据结构-链式队列

// link_queue_node.h
#ifndef LINK_QUEUE_NODE_H
#define LINK_QUEUE_NODE_H

#include <iostream>

template<typename Type> class LinkQueue;

template<typename Type> class QueueNode
{
private:
    friend class LinkQueue<Type>;
    QueueNode(const Type item, QueueNode<Type> *next=NULL)
        : m_data(item), m_next(next){}
private:
    Type m_data;
    QueueNode<Type> *m_next;
};

#endif // LINK_QUEUE_NODE_H

// link_queue.h
#ifndef LINK_QUEUE_H
#define LINK_QUEUE_H

#include "link_queue_node.h"

template<typename Type> class LinkQueue
{
public:
    LinkQueue() : m_prear(NULL), m_pfront(NULL){}
    ~LinkQueue()
    {
        MakeEmpty();
    }

    void EnQueue(const Type item);
    Type DeQueue();
    void MakeEmpty();
    Type GetFront();
    void Print();
    bool IsEmpty() const
    {
        return (m_pfront == NULL);
    }

private:
    QueueNode<Type> *m_prear, *m_pfront;
};

template<typename Type> void LinkQueue<Type>::EnQueue(const Type item)
{
    if(m_pfront == NULL)
    {
        m_pfront = m_prear = new QueueNode<Type>(item);
    }
    else
    {
        m_prear = m_prear->m_next = new QueueNode<Type>(item);
    }
}

template<typename Type> Type LinkQueue<Type>::DeQueue()
{
    if(IsEmpty())
    {
        std::cout << __FUNCTION__ << " error : queue is empty " << std::endl;
        exit(1);
    }
    Type tmp = m_pfront->m_data;
    QueueNode<Type> *pdel = m_pfront;
    m_pfront = m_pfront->m_next;
    delete pdel;
    return tmp;
}

template<typename Type> void LinkQueue<Type>::MakeEmpty()
{
    QueueNode<Type> *pdel;
    while(m_pfront)
    {
        pdel = m_pfront;
        m_pfront = pdel->m_next;
        delete pdel;
    }
}

template<typename Type> Type LinkQueue<Type>::GetFront()
{
    if(IsEmpty())
    {
        std::cout << __FUNCTION__ << " error : queue is empty " << std::endl;
        exit(1);
    }
    return m_pfront->m_data;
}

template<typename Type> void LinkQueue<Type>::Print()
{
    using std::cout;
    using std::endl;
    QueueNode<Type> *pCursor = m_pfront;
    cout << "front";
    while(pCursor)
    {
        cout << "--->" << pCursor->m_data;
        pCursor = pCursor->m_next;
    }
    cout << "--->rear" << endl << endl << endl;
}

#endif // LINK_QUEUE_H

// main.cpp
#include <iostream>
#include "link_queue.h"

using namespace std;

int main(int argc, char *argv[])
{
    LinkQueue<int> queue;
    int init[10] = {1, 3, 5, 7, 9, 11, 13, 15, 17, 19};
    for(int i = 0; i < 10; i++)
    {
        queue.EnQueue(init[i]);
    }
    queue.Print();

    cout << "dequeue : " << queue.DeQueue() << endl;
    queue.Print();

    cout << "get front : " << queue.GetFront() << endl;
    queue.Print();

    queue.MakeEmpty();
    queue.Print();
    return 0;
}