Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns in JavaScript

Reverse Linked List

Explore the process of reversing a singly linked list by manipulating it in-place. This lesson helps you understand how to update the linked list head efficiently while working within given constraints, preparing you for common coding interview challenges.

We'll cover the following...

Statement

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

Constraints:

Let n be the number of nodes in a linked list.

  • 1≤1 \leq n ≤500\leq 500
  • −5000≤-5000 \leq Node.value ≤5000\leq 5000

Examples

Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Technical Quiz
1.

What is the output if the following linked list is provided as input?

4 → 2 → 7 → 8 → 9 → 0 → 2

A.

9 → 0 → 2 → 8 → 4 → 2 → 7

B.

7 → 2 → 4 → 8 → 2 → 0 → 9

C.

2 → 0 → 9 → 8 → 7 → 2 → 4

D.

0 → 2 → 2 → 4 → 8 → 9

1 / 4

Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.
1
2
3
4
5

Try it yourself

Implement your solution in the following coding playground.

JavaScript
usercode > main.js
// Definition for a Linked List node

// class ListNode {

//     constructor(val = 0, next = null) {

//         this.val = val;

//         this.next = next;

//     }

// }



import {ListNode} from './ds_v1/LinkedList.js';



function reverse(head) {



    // Replace this placeholder return statement with your code

    return head;

}



export {

    reverse

};
Reverse Linked List