代码
class Solution
{
public:
ListNode *deleteDuplicates(ListNode *head)
{
map<int, bool> flagMap;
if(head==NULL)
return head;
flagMap.clear();
ListNode *p = head;
ListNode *pre = NULL;
while(p!=NULL)
{
if(flagMap.find(p->val)!=flagMap.end())
{
pre->next = p->next;
p = p->next;
}
else
{
flagMap[p->val] = true;
pre = p;
p = p->next;
}
}
return head;
}
};