Fold List on Itself

Statement

Given the head of a singly linked list, reorder the list as if it were folded on its back. For example, if the list is represented as:

$L_{0}$ → $L_{1}$ → $L_{2}$ → … → $L_{n-2}$ → $L_{n-1}$ → $L_{n}$

We’ll reorder it as follows:

$L_{0}$ → $L_{n}$ → $L_{1}$ → $L_{n - 1}$ → $L_{2}$ → $L_{n - 2}$ → …

We may not modify the values in the list’s nodes. Only the links between nodes may be changed.