[Linked List] Remove duplicates from Sorted List II

Total accepted:59433 Total submissions:230628 difficulty:medium

Given a sorted linked list, delete all nodes that has duplicate numbers, leaving only distinct numbers from the Original list.

For example,
Given 1->2->3->3->4->4->5 , return 1->2->5 .
Given 1->1->1->2->3 , return 2->3 .

/** Definition for singly-linked list. * struct ListNode {* int val; * ListNode *next; * ListNode (int x) : Val (x), Next (NULL) {}}; */classSolution { Public: ListNode* Deleteduplicates (listnode*head) {ListNode* delete_from=null,*delete_to=NULL; ListNode* Pre =null,*cur=head,*cur_next=NULL;  while(cur) {cur_next= cur->Next; /*find the same chain string*/            BOOLHas_found =false;  while(Cur_next && Cur_next->val = = cur->val) {Cur_next= cur_next->Next; Has_found=true; }                        /*if a continuous repeating element is found, the chain of duplicate values is removed, and if the update predecessor node is not found*/            if(has_found) {Delete_from=cur; Delete_to=Cur_next;  while(Delete_from! =delete_to) {ListNode* tmp = delete_from->Next; Delete(Delete_from); Delete_from=tmp; } Pre? Pre->next=cur_next:head =Cur_next; }Else{Pre=cur; } cur=Cur_next; }        returnHead; }};

Next challenges: (m) Convert Sorted list to Binary Search Tree (m) Reorder list (m) insertion Sort List

[Linked List] Remove duplicates from Sorted List II