[Leetcode] Remove duplicate from sorted list II remove duplicate nodes from the sorted list

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

For example,
Given1->2->3->3->4->4->5, Return1->2->5.
Given1->1->1->2->3, Return2->3.

The difference between this and the remove duplicate from sorted list is that, in this case, as long as the node is duplicated, the value of the equal node will be deleted, leaving one in the title does not delete.

Idea: There may be changes to the table header (such as: 1->1->-1>2>3), generally modify the header of the topic will need a secondary pointer, so to create a new node. Traversing the linked list, encountering equal adjacent nodes, directly continue to traverse, encountered unequal two adjacent nodes, if the pre->next=cur description cur No duplicates, pre=pre->next can, if not equal to the description, there may be duplicates, then, The pre connects Cur but the pre does not move and needs to re-enter the loop to verify that there are no duplicates (no duplicates, pre->next=cur) until there are no duplicate nodes. Source

1 classSolution {2  Public:3ListNode *deleteduplicates (ListNode *head)4     {5         if(Head==null)returnhead;6 7ListNode *newlist=NewListNode (-1);8newlist->next=head;9ListNode *pre=NewList;TenListNode *cur=head; One  A          while(cur) -         { -              while(cur->next&&pre->next->val==cur->next->val) the             { -Cur=cur->Next; -             } -  +             if(pre->next==cur) -Pre=pre->Next; +             Else A             { atPre->next=cur->Next; -             } -  -Cur=cur->Next; -         } -         returnNewlist->Next; in     } -};

[Leetcode] Remove duplicate from sorted list II remove duplicate nodes from the sorted list