328.奇偶链表

奇偶链表

给定单链表的头节点 head，将所有索引为奇数的节点和索引为偶数的节点分别组合在一起，然后返回重新排序的列表。

解析

var oddEvenList = function (head) {
  if (!head) return head;
  let odd = head, even = head.next, evenHead = even;
  while (even && even.next) {
    odd.next = even.next; odd = odd.next;
    even.next = odd.next; even = even.next;
  }
  odd.next = evenHead;
  return head;
};