#ifndef DBLYLIST_H
#define DBLYLIST_H

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

template <typename T>
struct Node
{
    T key;
    Node *next, *prev;
};
template <typename T>
class DblyList
{
    public:
    DblyList();
    ~DblyList();
    Node<T>* insert(const T&);
    Node<T>* insert(Node<T>*, const T&);
    Node<T>* remove(Node<T>*);

    //Add the following
    Node<T>* begin() const
    {
        return head->next;
    }
    Node<T>* end() const
    {
        return head;
    }
    T& front()
    {
        return head->next->key;
    }
    T& back()
    {
        return head->prev->key;
    }

    size_t size() const
    {
        return length;
    }

    private:
    std::Node<T>* head;
    size_t length = 0;
};

template <typename T>
Node<T>* DblyList<T>::insert(Node<T>* pos, const T& item)
{
    Node<T> *tmp = new Node<T> {pos->next, post, item};
    pos->next->prev =tmp;
    pos->next=tmp;
    ++length;
    return tmp;
}//which inserts at the front of the list

template <typename T>
Node<T>* DblyList<T>::insert(const T& item)
{
    return insert(head, item);
}//which inserts a value after the given node and returns a pointer to the inserted node

template <typename T>
Node<T>* DblyList<T>::remove(Node<T>* item)
{
    Node<T> *left = item-> prev, *right = item->next;
    delete item;
    left-> next = right;
    right -> prev = left;
    return left;
    --length;
}//which removes the given node from the list and returns the previous node,



#endif