328.odd-even-linked-list.js

/*
 * @lc app=leetcode id=328 lang=javascript
 *
 * [328] Odd Even Linked List
 */

// @lc code=start
/**
 * 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 {ListNode}
 */
var oddEvenList = function (head) {
  if (!head) {
    return head
  }
  let evenHead = head.next
  let odd = head, even = evenHead
  while (even && even.next) {
    odd.next = even.next;
    odd = odd.next;
    even.next = odd.next;
    even = even.next;
  }
  odd.next = evenHead
  return head
};
// @lc code=end