Dataford
Interview QuestionsInterview GuidesExperiencesMock InterviewsPricing
Get started

Linked List Reversal

EasyPython00:00
Practice interviewer
In session
5 left
00:00

Your question is Linked List Reversal. Start with the requirements on the right.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

You need to log in / sign up to run or submit.

Problem

Given the head of a singly linked list, reverse the list and return the new head.

Implement a function that takes the head node of the list and returns the head node after reversal. The list nodes are defined as:

  • val: integer value stored in the node
  • next: reference to the next node, or None

Constraints

  • 0 <= number of nodes <= 10^5
  • -10^9 <= Node.val <= 10^9
  • The list may be empty
  • Reverse the list in-place using O(1) extra space

Function Signature

def reverse_linked_list(head):
Your solutionPython 3
You need to log in / sign up to run or submit.
Run your code to see test output