leetcode--Partition List

Given a linked list and a value x, partition it such that all nodes less than
x come before nodes greater than or equal to x.

You should preserve the original relative order of the nodes in each of the two partitions.

For example,

Given

1->4->3->2->5->2

and x = 3,

return

1->2->2->4->3->5

./**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode partition(ListNode head, int x) {
ListNode first = new ListNode(0);
ListNode second = new ListNode(0);
ListNode res = first;
ListNode res2 = second;
ListNode cur = head;
while(cur!=null){
if(cur.val<x){
first.next = cur;
cur = cur.next;
first.next.next = null;
first = first.next;
}else{
second.next = cur;
cur = cur.next;
second.next.next = null;
second = second.next;
}
}
first.next = res2.next;
return res.next;
}
}