Double Linked List

Double Linked List

• Doubly Linked List is second type of Linked list.
• We can navigate in both ways, either forward and backward.
• A single linked list node as two parts: Info and Next
• In double linked list has three parts: Info, Next, and Prev
  
• Info − Each node of a linked list can store a data called an element or information.
• Next − Each node of a linked list contains a link to the next link called Next.
• Prev − Each node of a linked list contains a link to the previous link called Prev.
• LinkedList − A Linked List contains the connection link to the first link called First or Head and to the last link called Last or Leaf.
• Characteristics:
• The first node has the following properties:
• Prev - link to be NULL
• Info - actual value that store in node
• Next - link to next node
• The last node has the following properties.
• Prev - link to prev node
• Info - actual value that store in node
• Next - link to be NULL
• The each node has the following properties.
• Prev - link to the previous node
• Info - actual value that store in node
• Next - link to next node
• Basic Operations: The following are the basic operations supported by a list.
• Insertion − 
• Insert Begin - Adds an element at the beginning of the list.
  
• Insert Last − Adds an element at the end of the list.
  
• Insert desired position - Add an element as per given position.
  

• Deletion − 
• Delete Begin - Deletes an element at the beginning of the list.
  
• Delete Last − Deletes an element from the end of the list.
  
• Delete (Key)− Deletes an element from the list using the key.
• Delete (Position) - Deletes an elements as per given position.
  
• Display 
• Forward − Displays the complete list in a forward manner.
• Backward − Displays the complete list in a backward manner.

In C, Example: 

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