#include<iostream>
using namespace std;
typedef int QElemtype;
//存储结构
typedef struct QNode{
	QElemtype data;
	struct QNode *next;
}QNode,*Queueptr;
 
typedef struct{
	Queueptr front;
	Queueptr rear;
}Linkqueue;
//初始化
int Initqueue(Linkqueue &Q){
	Q.front=Q.rear=new QNode;
	Q.front->next=NULL;
	return 1;
}
//入队
int Enqueue(Linkqueue &Q,QElemtype e){
	QNode *p;
	p=new QNode;
	p->data=e;
	p->next=NULL;Q.rear->next=p;
	Q.rear=p;
	return 1;
}
//出队
int Dequeue(Linkqueue &Q,QElemtype e){
	if(Q.front==Q.rear) return 0;
	QNode *p;
	p=Q.front->next;
	e=p->data;
	Q.front->next=p->next;
	if(Q.rear==p) Q.rear=Q.front;
	delete p;
	return 1;
}
//取头元素
int Gethead(Linkqueue Q){
	if(Q.front!=Q.rear){
		return Q.front->next->data;
	}
}
//遍历
void Output(Linkqueue Q)
{
	QNode *p = Q.front->next;
	while (p !=NULL)
	{
		int x = p->data;
		cout << x << " ";
		p = p->next;
	}
	cout << endl;
}
//main
int main(){
	Linkqueue Q;
	QElemtype e;
	Initqueue(Q);
	Enqueue(Q,1);
	Enqueue(Q,2);
	Enqueue(Q,3);
	Dequeue(Q,e);
	Output(Q);
	cout<<Gethead(Q)<<endl;
	return 0;
}