C++链式队列

//链式队列
#include<iostream>
using namespace std;
typedef int elemType;

struct QNode
{
    elemType data;
    QNode *next;
};

struct LinkQueue
{
    QNode *front;
    QNode *rear;
};

//初始化
void InitQueue(LinkQueue *q)
{
    q->front = q->rear = new QNode;
    q->front->next = NULL;
}

//插入元素e为队列新的队尾元素
void EnQueue(LinkQueue *q, elemType e)
{
    QNode *p = new QNode;
    p->data = e;
    p->next = NULL;
    q->rear->next = p;
    q->rear = p;
}

//删除队友元素，并打印其值
void DeQueue(LinkQueue *q)
{
    QNode *p = q->front->next;
    if(q->front==q->rear)
        cout<<"队列为空"<<endl;
    else
    {
        elemType x = p->data;
        cout<<"删除队头元素： "<<x<<endl;
        q->front->next = p->next; 
        if(q->rear == p)
            q->rear = q->front;
        delete p;
    }
}

//遍历队列
void TraQueue(LinkQueue *q)
{
    QNode *p = q->front->next;
    int i = 1;
    if(q->front==q->rear)
        cout<<"队列为空"<<endl;
    else
    {
        while(p!=q->rear)
        {
            cout << i <<":\t"<<p->data<<endl;
            p = p->next;
            i++;
        }
        cout << i <<":\t"<<q->rear->data<<endl;
    }
}

//清空队列
void ClearQueue(LinkQueue *q)
{
    if(q->front==q->rear)
        cout<<"出错，队列已经为空"<<endl;
    else
    {
        q->rear->next = q->front;
        delete(q->front);
        q->front = q->rear;
    }
}

//求队列长度
int LengthQueue(LinkQueue *q)
{
    QNode *p = q->front->next;
    int length = 0;
    if(q->front!=q->rear)
    {
        while(p)
        {
            length++;
            p = p->next;
        }
    }
    return length;
}

int main()
{
    LinkQueue q;
    InitQueue(&q);
    for(int i=1;i<7;i++)
        EnQueue(&q,i);
    int length = LengthQueue(&q);
    cout <<"队列长度为： "<< length <<endl;
    TraQueue(&q);
    cout<<endl;

    DeQueue(&q);
    TraQueue(&q);
    cout<<endl;

    for(int i=0;i<5;i++)
        DeQueue(&q);
    TraQueue(&q);
    cout<<endl;

    return 0;
}