题解 | #删除有序链表中重复的元素-II#

ListNode* deleteDuplicates(ListNode* head) 
    {
        ListNode*pre = new ListNode(0);
        pre->next = head;
        ListNode*p=pre, *q=head;
        while(p->next!=nullptr && p->next->next!=nullptr)
        {
            if(p->next->val == p->next->next->val)
            {
                q = p->next->next;
                while(q!=nullptr && q->val == p->next->val)   q = q->next;//找到不同就返回
                p->next = q;
            }
            else  p = p->next;
        }
        return pre->next;
    }