LeetCode 328 Odd Even Linked List

用到了两个dummy node。
 1 public class Solution {
 2   public ListNode oddEvenList(ListNode head) {
 3     // Write your solution here
 4     if (head == null || head.next == null) {
 5         return head; 
 6     }
 7         ListNode odd = new ListNode(0);
 8     ListNode oddTail = odd;
 9     ListNode even = new ListNode(0);
10     ListNode evenTail = even;
11     ListNode cur = head;
12     while (cur != null) {
13         if (cur.value % 2 == 1) {
14           oddTail.next = cur;
15         oddTail = oddTail.next;
16       } else {
17            evenTail.next = cur;
18         evenTail = evenTail.next;
19       }
20       cur = cur.next;
21     }
22     oddTail.next = even.next;
23     evenTail.next = null;
24     return odd.next;
25   }
26 }