Reverse a linked list without using extra space. The tail node becomes the head.

Reverse a linked list without using extra space. Example Input: 10 21 33 42 89 Output: 89 42 33 21 10 There can be many solutions to print the linked list in reverse order, like recursive approach (use extra space), reverse the Nov 4, 2019 · Time Complexity: O (N) where N is the number of nodes in the Linked Lists. In this comprehensive guide, we’ll explore the in-place reversal of a linked list, a technique that allows us to reverse the list without using additional data structures. Mar 29, 2024 · Given a Linked List, display the linked list in reverse without using recursion, stack or modifications to given list. Every node’s next pointer should point to its previous node. How to identify? This approach is quite useful when dealing with reversal of Linked Lists when there is a constraint to do it without using extra memory. The goal is to reverse the linked list such that: The head node becomes the tail. If it is a doubly linked list (DLL), you also need to swap the previous pointers. When the problem gives this constraint and Linked Lists data structure, you should think about In-place . Requires Oct 3, 2012 · In a job interview I was asked to write a function in C that recursively reverses a linked list, returns the new first node, and doesn't use any new nodes. Space Complexity: O (1), algorithm runs in constant space. One common operation on linked lists is reversing their order. How can you do this? Linked lists are fundamental data structures in computer science, and understanding how to manipulate them efficiently is crucial for any programmer. Examples: Input: 1->2->3->4->5->NULL Output: 5 4 3 2 1 Input: 10->5->15->20->24->NULL Output: 24 20 15 5 10 Below are different solutions that are now allowed here as we cannot use extra space and modify list. It’s essential to understand how to reverse a list in-place, meaning, without using extra memory. Approach 1: Reversing a Singly Linked List (SLL) Logic Given a singly linked list like Aug 22, 2019 · The task is to print the nodes starting from the end of the linked list without using extra space which means there shouldn’t be any extra variable instead the head pointer pointing the first node will be moved. This Jun 1, 2025 · Reversing a linked list is a classic problem that appears in many interviews. The tail node becomes the head. 1) Recursive solution to print reverse a linked list. bgvgf mpc ttzssmo vsovy obzbzgb wufire vtnhmrr vvvlaigg weo gdo