Understanding insertion at beginning

Inserting a node at the beginning of a doubly linked list is similar to inserting a node at the beginning of a singly linked list. The main difference is that a doubly linked list has two references stored in a node, and we need to keep track of both references. Let's examine the scenarios we need to take into account.

1. The list is empty

In this scenario, if the linked list is empty, the head will be null. We need to initialize the head node of the linked list and ensure that the next and previous pointers of this newly created head node are null, as this node is also the tail node of the list.