LeetCode之Remove Duplicates from Sorted List

ListNode *deleteDuplicates(ListNode *head) //Remove Duplicates from Sorted List II 
	{
		if(head==NULL||head->next==NULL) return head;		
		ListNode* cur=head,*pre;
		ListNode dummy(INT_MIN);
		pre=&dummy;		
		while (cur!=NULL)
		{
			bool duplicate=false;
			while (cur->next!=NULL&&cur->val==cur->next->val)
			{
				duplicate=true;
				ListNode* tmp=cur;
				cur=cur->next;
				delete tmp;
			}
			if (duplicate==true)
			{
				ListNode* tmp=cur;
				cur=cur->next;
				delete tmp;
				continue;
			}
			pre->next=cur;
			cur=cur->next;
			pre=pre->next;
		}
		pre->next=cur;
		return dummy.next;
	}