/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode* deleteDuplicates(ListNode* head) {
if(head==NULL||head->next==NULL)
return head;
ListNode* p=head;
ListNode* q=head->next;
while(q!=NULL)
{
if(p->val==q->val)
q=q->next;
else
{
p->next=q;
p=q;
q=q->next;
}
}
p->next=NULL;
return head;
}
};
