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 in 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.
Return the reordered list as an array.
Example 1:
Input: head = [1,2,3,4]
Output: [1,4,2,3]
Explanation: The list is reordered from 1→2→3→4 to 1→4→2→3.
Example 2:
Input: head = [1,2,3,4,5]
Output: [1,5,2,4,3]
Explanation: The list is reordered from 1→2→3→4→5 to 1→5→2→4→3.
Example 3:
Input: head = [1]
Output: [1]
Explanation: A single node needs no reordering.
[0, 5 × 10⁴]1 <= Node.val <= 1000