Coding Fundamentals

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.