leetcode（java）

86 
class Solution {
    public ListNode partition(ListNode head, int x) {
        ListNode lowheader=new ListNode(0);
        ListNode low=lowheader;
        ListNode highheader=new ListNode(0);
        ListNode high=highheader;
        while(head!=null){
            if(head.val<x){
                low.next=head;
                head=head.next;
                low=low.next;
                low.next=null;
            }else{
                high.next=head;
                head=head.next;
                high=high.next;
                high.next=null;
            }
        }
        low.next=highheader.next;
        return lowheader.next;
                
    }
}