83. Remove Duplicates from Sorted List

/**

?*?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)return?head;

????????ListNode*p=head;

????????ListNode*q=head->next;

????????while(q!=NULL){

????????????if(q->val!=p->val){

????????????????p->next=q;

????????????????p=p->next;

????????????}

????????????q=q->next;

????????}

????????p->next=NULL;

????????return?head;

????}

};