You are given the head of a singly linked-list: `L0 → L1 → … → Ln - 1 → Ln`
Reorder it to: `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.
Examples
Example 1
Input:
head = [1,2,3,4]Output:
[1,4,2,3]Example 2
Input:
head = [1,2,3,4,5]Output:
[1,5,2,4,3]Constraints
- •
The number of nodes in the list is in the range [1, 5 * 10^4]. - •
1 <= Node.val <= 1000
Code Editor