Introduction to Doubly Linked List
Doubly Linked List: Fundamentals DSA practice problem on Onlearn.
Difficulty: easy.
Topics: Doubly Linked Lists: Structure, Comparison with Singly Linked Lists, and Node Implementation, Data Structures, Linked List, Singly Linked List, Doubly Linked List, Node, Pointer, Time Complexity, Space Complexity, general programming, node structure, linked list, traversal, Node, Pointers & References, Linked List Operations.
Problem: Convert Singly Linked List to Doubly Linked List You are given the head of a singly linked list. Your task is to modify the list in place such that it becomes a doubly linked list. In a doubly linked list, each node has two pointers: next (pointing to the subsequent node) and back (pointing to the preceding node). For the head node, its back pointer should be null. Assume the Node structure for the singly linked list is initially: Your task is to populate the back pointer for each node, effectively transforming it into a doubly linked list where each node conceptually has: Input Specification: The input will be the head node of a singly linked list. Output Specification: Return the head node of the modified list, which should now be a valid doubly linked list.