#ifndef linkedlist_h
#define linkedlist_h
#include <cstdlib>
#include <iostream>

template<class T>
class LinkedList {
  class ListNode {
  public:
	ListNode *next, *prev;
	T data;
  };
  
 public: class Iterator {
	LinkedList<T> *list;
  public:
	ListNode *current;
	void next() {current = current->next;}
	T &data() {return current->data;}
	bool isValid(){return current!=list->tail;};
	Iterator (LinkedList<T> &_list) {list = &_list; current=list->head->next;}
  };
  
  ListNode *head, *tail;
 public:
  LinkedList();
  void add (const T &data);
  bool isEmpty();
  void remove(Iterator &i);
};




#endif