Reorder List

Problem statement

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.

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 * 104].
• 1 <= Node.val <= 1000

My solution

/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @return {void} Do not return anything, modify head in-place instead.
 */
var reorderList = function(head) {
    const listArr = []
    
    while (head) {
        listArr.push(head);
        head = head.next
    }
    
    
    let left = 0;
    let right = listArr.length - 1;
    
    while (left < right) {
        listArr[left].next = listArr[right]
        listArr[right].next = (left + 1 !== right) ? listArr[left + 1] : null;
        left++;
        right--
    }
    
    if (left == right) {
        listArr[left].next = null;
    }
    
    return head;
};