Circular Single Linked List, Doubly Linked List, & Circular Doubly Linked List

Circular Single Linked List

• In circular, last node contains a pointer to the first node

• We can have a circular singly linked list as well as a circular doubly linked list.

• There is no storing of NULL values in the list

Advantages of Circular Linked Lists:
1) Any node can be a starting point.
2) Useful for implementation of queue.
3) Circular lists are useful in applications to repeatedly go around the list.
4) Circular Doubly Linked Lists are used for implementation of advanced data structures like Fibonacci Heap.

Doubly Linked List

• Double/Doubly linked list (DLL) or two-way linked list is a linked list data structure with two link, one that contain reference to the next data and one that contain reference to the previous data.

Following is representation of a DLL node in C language.




/* Node of a doubly linked list */

struct Node {

    int data;

    struct Node* next; // Pointer to next node in DLL

    struct Node* prev; // Pointer to previous node in DLL

};

Advantages over singly linked list:

1) A DLL can be traversed in both forward and backward direction.

2) The delete operation in DLL is more efficient if pointer to the node to be deleted is given.

3) We can quickly insert a new node before a given node.

Disadvantages over singly linked list
1) Every node of DLL Require extra space for an previous pointer.

2) All operations require an extra pointer previous to be maintained.

Doubly Linked List: Insertion 

A node can be added in four ways:
1) At the front of the DLL.
2) After a given node.
3) At the end of the DLL.
4) Before a given node.

Doubly Linked List: Deletion

There are 4 conditions we should pay attention when deleting:

1) The node to be deleted is the only node in linked list.

2) The node to be deleted is head.

3) The node to be deleted is tail.

4) The node to be deleted is not head or tail.

Circular Doubly Linked List

Circular Doubly Linked List has properties of both doubly linked list and circular linked list in

which two consecutive elements are linked or connected by previous and next pointer and

the last node points to first node by next pointer and also the first node points to last node

by previous pointer.

That is my summary for Data Structure Session 3 on 24th February 2020, Thank you


Source:

https://www.geeksforgeeks.org/
https://www.geeksforgeeks.org/circular-linked-list/
https://www.geeksforgeeks.org/doubly-linked-list/
https://www.geeksforgeeks.org/doubly-circular-linked-list-set-1-introduction-and-insertion/