链式队列的C++实现

/*
 * queue.cpp
 *
 *  Created on: 2012-5-13
 *      Author: awind
 *      队列的链式表示
 */


#include
#include

using namespace std;

typedef struct QNode{
    int data;
    struct QNode *next;
}QNode,*QueuePtr;

typedef struct{
    QueuePtr front; //队头指针
    QueuePtr rear;  //队尾指针
}LinkQueue;

bool InitQueue(LinkQueue &Q) //创建一个空队列
{
    Q.front=Q.rear=new QNode;
    if(!Q.front)
        return false;
    Q.front->next=NULL;
    return true;
}

bool DestroyQueue(LinkQueue &Q)  //销毁队列
{
    while(Q.front){
        Q.rear=Q.front->next;
        delete Q.front;
        Q.front=Q.rear;
    }
    return true;
}

bool EnQueue(LinkQueue &Q,int e) //插入元素为e的新的队尾元素
{
    QNode *p=new QNode;
    if(!p)
        return false;
    p->data=e;
    p->next=NULL;
    Q.rear->next=p;  //尾指针指向插入的元素
    Q.rear=p;   //插入的元素成为尾指针
    return true;
}


bool DeQueue(LinkQueue &Q,int &e)  //若队列不为空，则删除Q的队头元素
{
    if(Q.front==Q.rear)
        return false;
    QNode *p=new QNode;
    p=Q.front->next;
    e=p->data;
    Q.front->next=p->next;
    if(Q.rear==p)
        Q.rear=Q.front;
    delete p;
    return true;
}

bool QueueEmpty(LinkQueue Q)  //队列是否为空
{
    return Q.front==Q.rear;
}

bool ClearQueue(LinkQueue &Q)  //将队列清空
{
    QNode *p=new QNode;
    p=Q.front->next;

    while(p)
    {
        Q.rear=p->next;
        delete p;
        p=Q.rear;
    }
    Q.rear=Q.front;
    Q.front->next=NULL;
    return true;
}

int QueueLength(LinkQueue Q) //返回队列的长度
{
    int count=0;
    if(Q.front==Q.rear)
        return 0;

    QNode *p=new QNode;
    p=Q.front->next;
    while(p)
    {
        ++count;
        p=p->next;
    }
    return count;
}


bool GetHead(LinkQueue Q,int &e)  //若队列不为空 则用e返回Q的队头元素
{
    if(Q.front==Q.rear)
        return false;
    e=Q.front->next->data;
    return true;
}

bool QueueTraverse(LinkQueue Q)
{
    if(Q.front==Q.rear)
        return false;
    QNode *p=new QNode;
    p=Q.front->next;
    while(p)
    {
        cout<data<<" ";
        p=p->next;
    }
    return true;
}


int main()
{
    LinkQueue Q;
    InitQueue(Q);
    cout<<"input the num of the Queue: ";

    int stackNum;
    cin>>stackNum;
    for(int i=0;i
    {
        int elem;
        cout<<"input the element of the stack: ";
        cin>>elem;
        EnQueue(Q,elem);
    }

    QueueTraverse(Q);
    cout<<"\n";
    cout<<"the length of the Queue: "<

    ClearQueue(Q);


    cout<<"input the num of the Queue: ";


        cin>>stackNum;
        for(int i=0;i
        {
            int elem;
            cout<<"input the element of the stack: ";
            cin>>elem;
            EnQueue(Q,elem);
        }

        QueueTraverse(Q);
        cout<<"\n";
        cout<<"the length of the Queue: "<

    }