Reorder List (#143)
You are given the head of a singly linked-list. The list can be represented as:
L0 → L1 → … → Ln-1 → Ln
Reorder the list to be on the following form:
L0 → Ln → L1 → Ln-1 → L2 → Ln-2 → …
You may not modify the values in the list's nodes. Only nodes themselves may be changed.
Company Tags: Amazon, Facebook
Core Concept: Linked List, Two-Pointer