循环队列//输入输出

#include<iostream>
using namespace std;
#define maxsize 3    //有用？
typedef struct
{
	int data[maxsize];     //注意 int* data;
	int front;
	int rear;
}squeue;
void init(squeue& q)
{
	q.front = 0;
	q.rear = 0;
}
int enqueue(squeue& q, int e)
{
	if (q.front == q.rear % maxsize)//队满标志 (rear+1)%MAXQSIZE==front
		return 0;
	q.data[q.rear] = e;
	q.rear = (q.rear + 1) % maxsize;
	return 1;
}
int dequeue(squeue& q, int& e)
{
	if (q.rear == q.front)
		return 0;
	e = q.data[q.front];
	q.front = q.front + 1 % maxsize;
	return 1;
}
int length(squeue q)               //求不了长度  待解决
{  
	return (q.rear - q.front + maxsize) % maxsize;
}
int GetHead(squeue Q)          //待解决
{
	if (Q.front != Q.rear)              //队列不为空
		return Q.data[Q.front];         //返回队头指针元素的值，队头指针不变
}
int main()
{
	squeue haha;
	init(haha);
	int n;
	int e;
	cout<<"::"; cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> e;
		enqueue(haha,e);
		dequeue(haha, e);
		cout << e << " ";
	
	}
	cout << length(haha);
	
}