A Doubly Linked List (DLL) is a type of data structure in which each node contains two links, one pointing to the next node and the other pointing to the previous node. This makes it possible to traverse the list in both forward and backward directions.
Here’s an example of a DLL:
NULL <- head tail -> NULL
NULL <- node0 <-> node1 <-> node2 <-> node3 -> NULL
NULL <- tail head -> NULL
In this DLL, we have four nodes, with each node having value and two pointers – prev and next. The head of the list is the node0 and the tail is node3.
One advantage of DLL is that it allows for insertion and deletion of nodes from both ends efficiently. For example, to insert a node between node0 and node1 in the above example, we simply create a new node, set its prev pointer to node0, and its next pointer to node1. Then, we update the prev pointer of node1 to point to the new node, and the next pointer of node0 to point to the new node.
Overall, DLL is useful in scenarios where we need to traverse a list in both directions or perform frequent insertions/deletions at both ends of the list.
A doubly linked list is a type of data structure that consists of nodes linked together in a specific order.
Unlike a singly linked list, each node in a doubly linked list has two pointers: one to the next node and one to the previous node.
This allows for bi-directional traversals through the list, as well as easier deletion and insertion of nodes.
A doubly linked list can be implemented using classes or structures in most programming languages.
Some common operations on a doubly linked list include insertion, deletion, and traversal.
Insertion and deletion of nodes in a doubly linked list can be faster than in a singly linked list, as only a few pointer updates are necessary.
However, doubly linked lists tend to use more memory than singly linked lists because of the extra pointer in each node.
Some advanced concepts related to doubly linked lists include circular doubly linked lists and doubly linked lists with a sentinel node.
What is a doubly linked list?
Answer: A doubly linked list is a type of data structure in which each node contains two pointers - one that points to the previous node in the list and one that points to the next node in the list.
How is a node added to the end of a doubly linked list?
Answer: To add a node to the end of a doubly linked list, you need to traverse the list until you reach the last node. then create a new node and set its previous pointer to point to the previous last node, and the next pointer of the previous last node to point to the new node.
What is the time complexity of searching for an element in a doubly linked list?
Answer: The time complexity of searching for an element in a doubly linked list is O(n) in the worst case, as you may need to traverse through the entire list to find the element.
What is the advantage of a doubly linked list over a singly linked list?
Answer: The advantage of a doubly linked list over a singly linked list is that you can traverse the list in both directions, which makes it easier to navigate and perform modifications, especially when dealing with large lists.
How is a node removed from a doubly linked list?
Answer: To remove a node from a doubly linked list, you need to update the previous node’s next pointer to point to the next node, and the next node’s previous pointer to point to the previous node. Then, you can free the memory of the node that you want to remove.