Queue---队列

/*Queue class declarations.*/#ifndef _QUEUE_H_#define _QUEUE_H_#include <iostream>using namespace std;typedef charElemType;typedef struct SNode{ElemTypedata;struct SNode*pNext;}Node;class CQueue{public:CQueue();boolEnQueue(ElemType elem);// insert an element at rearboolDeQueue(ElemType& elem);// delete an element at frontboolisEmpty();// if queue is empty return trueboolTraverse();// traverse the queueintitsLength();// get queue's length~CQueue();private:Node*rear;// only allow insert operationNode*front;// only allow delete operation};#endif // _QUEUE_H_

/*class definition.*/#include "queue.h"/*Parameter:noneReturn:noneDescription:class default constructor.*/CQueue::CQueue() {front=new Node;rear=front;rear->pNext=NULL;} // default constructor/*Parameter:ElemTypeReturn:true or falseDescription:insert an element to a queue's rear.*/boolCQueue::EnQueue(ElemType elem) {Node*pNode=new Node;pNode->data=elem;pNode->pNext=NULL;rear->pNext=pNode;rear=pNode;return true;} // EnQueue/*Parameter:ElemType&Return:true or falseDescription:if queue is not empty, delete the front element.*/boolCQueue::DeQueue(ElemType& elem) {Node*pNode;if (isEmpty()) {return false;}else {pNode=front->pNext;elem=pNode->data;front->pNext=pNode->pNext;return true;}} // DeQueue/*Parameter:noneReturn:true or falseDescription:if queue is empty return true.*/boolCQueue::isEmpty() {if (front == rear) return true;elsereturn false;} // isEmpty/*Parameter:noneReturn:queue lengthDescription:get queue's length.*/intCQueue::itsLength() {intiLen=0;Node*pNode=front;while (pNode != rear) {++iLen;pNode=pNode->pNext;}return iLen;} // itsLength/*Parameter:noneReturn:true or falseDescription:visit queue every element.*/boolCQueue::Traverse() {Node*pNode = front->pNext;while(pNode) {cout<<pNode->data<<endl;pNode=pNode->pNext;}return true;} // Traverse/*Parameter:noneReturn:noneDescription:destroy queue no matter empty or not.*/CQueue::~CQueue() {while(front) {rear=front->pNext;deletefront;front=rear;}} // default destructor

//-----------------------------------------------------------------------------//Copyright (c) 2009 eryar All rights reserved.////File:main.cpp//Author:[e-mail]//Date:2010-01-02//Version:1.0v////Description:Queue class implenment.////=============================================================================#include "queue.h"int main(int argc, char* argv[]) {charx, y;CQueuequeue;cout<<"queue length is : "<<queue.itsLength()<<endl;queue.EnQueue('a');queue.EnQueue('b');queue.EnQueue('c');queue.DeQueue(x);queue.DeQueue(y);cout<<"queue length is : "<<queue.itsLength()<<endl;cout<<"first DeQueue element is : "<<x<<endl;cout<<"then DeQueue element is : "<<y<<endl;queue.Traverse();return 0;}

 

Program output:

queue length is : 0
queue length is : 1
first DeQueue element is : a
then  DeQueue element is : b
c
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