题解 | #删除有序链表中重复的元素-II#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    ListNode* deleteDuplicates(ListNode* head)
    {
        if(head == nullptr)
        {
        return nullptr;
        }
     
        ListNode* newhead = new ListNode(0);
        newhead->next = head;
        ListNode* cur = newhead;
 
        while(cur->next && cur->next->next)
        {
            if(cur->next->val == cur->next->next->val)
            {
                int temp = cur->next->val;
                while(cur->next && cur->next->val == temp)
                {
                    cur->next = cur->next->next;
                }
            }
            else
            {
                cur = cur->next;
            }
        }
        return newhead->next;
    }
};