双端队列(链表表示)

 

#ifndef LINKEDDEQUE_H

#define LINKEDDEQUE_H

 

#include <iostream>

#include <assert.h>

using namespace std;

 

template<class T>

struct LinkNode        //链式队列节点类的定义

{

     T data;  //数据域

     LinkNode<T> *link; //链指针域

     LinkNode(LinkNode<T> *ptr = NULL)    //仅初始化指针成员的构造函数

     {

         link = ptr;

     }

     LinkNode(const T &item,LinkNode<T> *ptr = NULL)    //初始化数据与指针成员的构造函数

     {

         data = item;

         link = ptr;

     }

};

 

template<class T>

class LinkedDeque

{

public:

     LinkedDeque():front(NULL),rear(NULL){}

     ~LinkedDeque()

     {

         MakeEmpty();

     }

     void MakeEmpty();  //置空队列

     bool IsEmpty()const

     {

         return (front == NULL) ? true : false;

     }

     bool GetHead(T& x)const;

     bool GetTail(T& x)const;

     bool EnQueue(const T& x);

     bool EnQueueHead(const T& x);

     bool EnQueueTail(const T& x);

     bool DeQueue(T &x);

     bool DeQueueHead(T &x);

     bool DeQueueTail(T &x);

private:

     LinkNode<T> *front,*rear;   //队头、队尾指针

};

 

template<class T>

void LinkedDeque<T>::MakeEmpty()

{

     LinkNode<T> *p;

     while(front != NULL)

     {

         p = front;

         front = front->link;

         delete p;

     }

}

 

template<class T>

bool LinkedDeque<T>::GetHead(T &x) const

{

     if(IsEmpty() == true)

         return false;

     x = front->data;

     return true;

}

 

template<class T>

bool LinkedDeque<T>::EnQueueTail(const T &x)

{

     return EnQueue(x);

}

 

template<class T>

bool LinkedDeque<T>::DeQueueHead(T &x)

{

     T temp;

     bool tag = LinkedDeque<T>::DeQueue(temp);

     x = temp;

     return tag;

}

 

template<class T>

bool LinkedDeque<T>::GetTail(T& x)const

{

     if(IsEmpty() == true)

         return false;

     x = rear->data;

     return true;

}

 

template<class T>

bool LinkedDeque<T>::EnQueueHead(const T &x)

{

     LinkNode<T> *p = new LinkNode<T>(x);

     if(p == NULL)

         return false;

     p->link = front;

     front = p;

     return true;

}

 

template<class T>

bool LinkedDeque<T>::DeQueueTail(T &x)

{

     if(IsEmpty() == true)

         return false;

     LinkNode<T> *p = front;

     while(p->link != rear)

         p = p->link;

     x = rear->data;

     delete rear;

     p->link = NULL;

     rear = p;

     return true;

}

 

#endif