//	This is our old friend the list class.

template <class Etype> 
class LNode
{
	Etype value;
	LNode *next;
//	it is very important that X is passed by reference
//	otherwise a copy constructor is needed
	LNode(const Etype & X, LNode *n=NULL) { next=n; value=X; };
	friend class List<Etype>;
};

template <class Etype>
class List
{
	LNode<Etype> *head;
	LNode<Etype> *current;
	const Etype nulltype;			// a user specified value
						// that indicates a null value

	public:
	List() { current=head=NULL; };
	List(const Etype & nt) :  nulltype(nt) { current=head=NULL;};
	Etype First() { current=head; return current ? current->value : nulltype;};
	Etype operator++();
	Etype operator()() { return current ? current->value : nulltype; }; 
	void Insert(const Etype &);
	int Find(Etype);
	int IsCurrent() { return current ? 1: 0; };
};

template <class Etype>
Etype List<Etype>::operator++()
{
	if (current)
		current=current->next;
	return current ? current->value : nulltype;
}

template <class Etype>
void List<Etype>::Insert(const Etype & X)
{
	current=new LNode<Etype>(X,head);
	head=current;
}

template <class Etype>
int List<Etype>::Find(Etype X)
{
	current=head;
	while (current)
	{
		if (X==current->value)
			break;
		else
			current=current->next;
	}
	return (current!=NULL);		
}