Reverse a Linked List

Problem

Reverse the links in a singly linked list. Input/output use an array to represent node order.

Examples

Example 1

Input: [1,2,3]

Output: [3,2,1]

Example 2

Input: []

Output: []

Input and output use JSON-compatible values. For linked-list and tree questions, arrays represent the node structure as described above. Your code should implement solve(input).

Write your solutionImplement solve(input). Your draft is saved in this browser.

Compiler

How to solve Reverse a Linked List

Reverse the links in a singly linked list. Input/output use an array to represent node order. Use a previous pointer while traversing nodes. The reference implementation illustrates this approach; check the example and edge cases.

Time and space complexity

O(n) time; O(1) auxiliary space for pointer reversal (excluding serialized output).

Practise and improve

Choose JavaScript, TypeScript or Python, complete the starter code, then select Run Tests. Request a hint when you need guidance, or choose View solution and confirm if you would like to study the reference implementation.