实验2：链队列

#include<iostream>
using namespace std;
template<class datatype>
struct Node
{
	datatype data;
	Node<datatype> *next;
};

template <class datatype>
class link
{
private:
	Node<datatype> *front, *rear;
public:
	link()
	{
		Node<datatype> *s = NULL;
		s = new Node<datatype>;
		s->next = NULL;
		front = rear = s;
	}
	~link()
	{
		Node<datatype> *p = NULL;
		while (front != NULL)
		{
			p = front->next;
			delete front;
			front = p;
		}
	}
	void inqueue(datatype x)
	{
		Node<datatype> *s = NULL;
		s = new Node<datatype>;
		s->data = x;
		s->next = NULL;
		rear->next = s;
		rear = s;
	}
	datatype outqueue()
	{
		Node<datatype> *p = NULL;
		int x;
		if (rear == front) throw"下溢";
		p = front->next;
		x = p->data;
		front->next = p->next;
		if (p->next == NULL)
			rear = front;
		delete p;
		return x;
	}
	datatype getqueue()
	{
		if (front != rear)
			return front->next->data;
	}
	int empty()
	{
		if (front == rear)
			return 1;
		else
			return 0;
	}
};


void main()
{
	link<int> q;
	if (q.empty())
		cout << "队列为空" << endl;
	else
		cout << "队列非空" << endl;
	cout << "15，36，77入队" << endl;
	try
	{
		q.inqueue(15);
		q.inqueue(36);
		q.inqueue(77);
	}
	catch(char* wrong)
	{
		cout << "wrong" << endl;
	}
	cout << "队头元素：" << endl;
	cout << q.getqueue() << endl;
	cout << "执行出队操作：" << endl;
	try
	{
		q.outqueue();
	}
	catch (char* wrong)
	{
		cout << wrong << endl;
	}
	cout << "查看队头元素" << endl;
	cout << q.getqueue() << endl;
}