重复节点删除

public ListNode deleteDuplication(ListNode pHead)
    {
        if(pHead == null){
            return null;
        }

        //设置前置指针
        ListNode head = new ListNode(-1);
        head.next = pHead;
        ListNode pre = head;
        ListNode cur = head.next;

        //判断是否为null
        while(cur!=null){
            if(cur.next!=null && cur.val == cur.next.val){
                while(cur.next!=null && cur.val == cur.next.val){
                    cur = cur.next;
                }
                pre.next = cur.next;
                if(cur.next==null){
                    return head.next;
                }
                cur = cur.next;
            }else {
                pre = cur;
                cur = cur.next;
            }
        }
        return head.next;
    }