两个栈实现队列

#include<iostream>
#include<stack>
using namespace std;

template<class T> class myQueue
{
public:
	void In(T node);
	T Out();
private:
	stack<T> stack1;
	stack<T> stack2;
};

template<class T> void myQueue<T>::In(T node)
{
	stack1.push(node);
}

template<class T> T myQueue<T>::Out()
{
	if(stack2.size()<=0)
	{
		while (stack1.size()>0)
		{
			T &data = stack1.top();
			stack1.pop();
			stack2.push(data);
		}
	}
	if(stack2.size()<=0)
	{
		throw new exception("qeue is empty");
	}
	T head = stack2.top();
	stack2.pop();
	return head;
}

void main()                                                                                                   
{
	myQueue<int> myQ;
	myQ.In(1);
	myQ.In(2);
	myQ.In(3);
	cout<<myQ.Out()<<endl;
	cout<<myQ.Out()<<endl;
	cout<<myQ.Out()<<endl;
	system("pause");
}