Doubly linked list

Overview

Doubly linked list
Node
Insertion
Deletion

A doubly linked list is a type of linked list where each node maintains a reference to both the next node and the previous node in the sequence. This feature allows for both forward and backward traversal of the list. The first node’s previous reference and the last node’s next reference point to null
Below is an example implementation of a doubly linked list in Java:

Representation Of The Node In A Doubly Linked List

				
					struct node  
{  
  int data;  
  struct node *next;  
 struct node *prev;   
}

In the above representation, we have defined a user-defined structure named a node with three members, one is data of integer type, and the other two are the pointers, i.e., next and prev of the node type. The next pointer variable holds the address of the next node, and the prev pointer holds the address of the previous node. The type of both the pointers, i.e., next and prev is struct node as both the pointers are storing the address of the node of the struct node type.

Node

class node
{
node prev;
int item;
node next ;
}

Insertion

At first
At Last
After a node

Inset As A First Node

				
					node n = new node() ;
n .item = data;
n.prev = null;
n .next = start;
if ( start != null)
start.prev= n ;
start = n

Insert At Last

				
					node n = new node() ;
n. item = data;
n .next = null;
if( start == null)
{
n.prev=null
start=n;
}
else
{
temp=start;
while(temp.next!=null)
temp=temp.next;
temp.next=n;
}

Insert After A Node

Deletion

Delete First node
Delete Last node
Delete Specific node

Doubly linked list

Overview