328. 奇偶链表

中等

题目描述

解法：
定义两个指针，odd，even 交替移动，将经过的结点存贮给 odds 和 evens

class Solution {
    public ListNode oddEvenList(ListNode head) {
        if(head == null || head.next == null) return head;
        ListNode odd = head;
        ListNode even = head.next;
        ListNode odds = head;
        ListNode oddFir = odds;
        ListNode evens = head.next;
        ListNode evenFir = evens;
        while (true){
            if(even.next != null){
                odds.next = even.next;
                odd = even.next;
                odds = odds.next;
            }else {
                odd.next = null;
                odds.next = evenFir;
                return oddFir;
            }
            if(odd.next != null){
                evens.next = odd.next;
                even = odd.next;
                evens = evens.next;
            }else {
                even.next = null;
                odd.next = evenFir;
                return oddFir;
            }
        }
    }
}