/
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode next;
* ListNode(int x) : val(x), next(NULL) {}
* };
/
class Solution {
public:
ListNode deleteDuplication(ListNode head) {
auto dummy = new ListNode(-1);
dummy ->next = head;
auto p = dummy;
while (p->next)
{
auto q = p->next;
while (q->next && q->next->val == p->next->val) q = q->next;
if(q == p->next) p = q;
else p->next = q->next;
}
return dummy->next;
}
};