LeetCode 86 Partition List

需要两个dummy node来构造两个list：

一个是小于target的linked list

另一个是大于等于target的linked list

 1 public class Solution {
 2   public ListNode partition(ListNode head, int target) {
 3     if (head == null) {
 4          return head; 
 5     }
 6     // Write your solution here
 7     ListNode less = new ListNode(0);
 8     ListNode large = new ListNode(0);
 9     ListNode lessTail = less;
10     ListNode largeTail = large;
11     
12     ListNode cur = head;
13     while (cur != null) {
14       if (cur.value < target) {
15            lessTail.next = cur;
16         lessTail = lessTail.next;
17       } else {
18            largeTail.next = cur;
19         largeTail = largeTail.next;
20       }
21       cur = cur.next;
22     }
23     lessTail.next = large.next;
24     largeTail.next = null;
25     return less.next;
26   }
27 }