#include <stdio.h>
#include <stdlib.h>

class NODE
{
public:
	int data;
	NODE *previous;
	NODE *next;

	NODE(int data)
	{
		this->data=data;
		previous=NULL;
		next=NULL;
	}
};

class dlinkedlist
{
	NODE *first;
	NODE *back;
public:
	dlinkedlist()
	{
		first=NULL;
		back=NULL;
	}
	~dlinkedlist()
	{
		removeallnodes();
	}
	void addnode(int data)
	{
		NODE *n = new NODE(data);
		if (back==NULL)
		{
			back=n;
			first=n;
		}
		else
		{
			back->next=n;
			n->previous=back;
			back=n;
		}
	}
	void displaynodes()
	{
		printf("NODE : ");
		NODE *temp=first;
		while(temp!=NULL)
		{
			printf("%d ",temp->data);
			temp=temp->next;
		}
		printf("\n");
	}
	void displaynodereverse()
	{
		printf("NODE : ");
		NODE *temp=back;
		while(temp!=NULL)
		{
			printf("%d ",temp->data);
			temp=temp->previous;
		}
		printf("\n");
	}
	void removeallnodes()
	{
		NODE *temp=back;
		while(temp!=NULL)
		{
			NODE *n=temp;
			temp=temp->previous;
			delete n;
		}
		back=NULL;
		first=NULL;
	}
};

void main()
{
	dlinkedlist dlist;
	dlist.addnode(100);
	dlist.addnode(5);
	dlist.addnode(33);
	dlist.addnode(23);
	dlist.addnode(56);
	dlist.addnode(78);
	dlist.addnode(54);
	dlist.addnode(13);
	dlist.addnode(43);

	dlist.displaynodes();
	dlist.displaynodereverse();
}