Searching particular node in Doubly Linked List

Searching particular node in Doubly Linked List
//find()
#include<stdio.h>
#include<iostream.h>
#include<conio.h>
template<class T>
class node
{
 node<T> *llink;
 T data;
 node<T> *rlink;
 friend class dll<T>;
};
template <class T>
class dll
{
 private:
        node<T> *l,*r;
 public:
        dll();
       ~dll();
        int isempty();
        
        int length();
        
        T find(int i);

void append(node<T>*k);
void create();
};
template<class T>
dll<T>::dll()
{
 l=r=NULL;
}
template<class T>
int dll<T>::isempty()
{
 return(l==NULL);
}
//length()
template<class T>
int dll<T>::length()
{
 int ctr=0;
 node<T> *p;
 p=l;
 while(p!=NULL)
 {
  ctr++;
  p=p->rlink;
 }
 return(ctr);
}
//find()

template<class T>
T dll<T>::find(int i)
{
 node<T> *p;
 if(i<1||i>length())
  return(-1);
 p=l;
 for(int j=1;j<=i-1;j++)
  p=p->rlink;
 return(p->data);
}
//apend()
template <class T>
void dll<T>::append(node<T>* k)
{
 node<T> *last;
 k->rlink=NULL;
 if(isempty())
   l=r=k;
 else
 {
   last=r;
   while(last->rlink!=NULL)
   {
    last=last->rlink;
   }
   last->rlink=k;
  }
}
//create()
template<class T>
void dll<T>::create()
{
  T x;
  node<T> *k;
  l=r=NULL;
  cout<<"enter values terminated by -1 or !\n";
  cin>>x;
  while(x!=-1&&x!='!')
  {
   k=new node<T>;
   k->data=x;
   append(k);
   cin>>x;
  }
 }//create()
template<class T>
dll<T>::~dll()
{

}

main()
{
 dll<int>a;
 node<int>*p;
 int ch,i,x;
 clrscr();
 a.create();
 cout<<"enter value of i\n";
 cin>>i;
 x=a.find(i);
 if(x==-1)
   cout<<"non existing node\n";
 else
   cout<<"data of desired node is"<<x<<"\n";
  
getch();
return(0);

}//main()

Doubly Linked List Operations

Types of Linked list

1.     Single Linked List

2.    Doubly Linked List

3.    Circular Linked List 

Programs on Doubly Linked List

Node class structures

Some terminology of Doubly Linked List programs