LeetCode精選100題——第86題——分隔鏈表

class Solution {
    public ListNode partition(ListNode head, int x) {
        ListNode dummyHead1=new ListNode(-1);
        ListNode dummyHead2=new ListNode(-1);
        ListNode p1=dummyHead1;
        ListNode p2=dummyHead2;
        while(head!=null){
            if(head.val<x){
                p1.next=head;
                head=head.next;
                p1=p1.next;
            }else{
                p2.next=head;
                head=head.next;
                p2=p2.next;
            }
        }
        p1.next=null;
        p2.next=null;
        p1.next=dummyHead2.next;
        // dummyHead2.next=null;
        return dummyHead1.next;
    }
}