Given a sorted linked list, delete all duplicates such that each element appear only once.
For example,
Given 1->1->2
, return 1->2
.
Given 1->1->2->3->3
, return 1->2->3
.
class Solution { public: ListNode *deleteDuplicates(ListNode *head) { if(head==NULL) return NULL; ListNode *lp = head,*rp = head; while(rp!=NULL){ while(rp!=NULL&&rp->val==lp->val) rp=rp->next; lp->next = rp; lp = rp; } return head; } };