Reverse a Linked List in Groups of K
Company: ByteDance
Role: Machine Learning Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Technical Screen
Overview: Implement `reverse_k_group(values, k)` for a singly linked list represented by the array `values` in traversal order. Work through the function contract, boundary cases, correctness argument, and time and space complexity expected in a production-quality solution.