Leetcode 82, remove duplicates from sorted list 2

//2 pointers

    public ListNode deleteDuplicates(ListNode head) {        if(head == null)            return head;        ListNode dummy = new ListNode(0);        dummy.next = head;        ListNode pre = dummy;        ListNode cur = head;        while(cur!=null){            while(cur.next != null && pre.next.val == cur.next.val){                cur = cur.next;            }            if(pre.next==cur){                pre = pre.next;            }else{                pre.next = cur.next;            }            cur = cur.next;        }        return dummy.next;    }

refer: http://blog.csdn.net/linhuanmars/article/details/24389429