LeetCode: Remove Duplicates from Sorted List II

Given a sorted linked list, delete all nodes that have 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) {}  
  * };  
  */  

   typedef ListNode node; 

 
   ListNode *deleteDuplicates(ListNode *head) {  
     if(!head || !head->next)return head;  
     ListNode *prev = NULL,*cur = head, *newHead = NULL;  
     while(cur)  
     {  
       node *nxt = cur->next;  
       bool deleteCur = false;  
       while(nxt && nxt->val == cur->val)  
       {  
         deleteCur = true;  
         node *tmp = nxt;  
         cur->next = nxt->next;  
         nxt = nxt->next;  
         delete tmp;  
       }  
       if(deleteCur)  
       {  
         node *tmp = cur;  
         if(prev)  
           prev->next = nxt;  
         cur = nxt;  
         if(nxt)  
           nxt = nxt->next;  
         delete tmp;  
       }  
       else  
       {  
         if(!prev)newHead = cur;  
         prev = cur;  
         cur = nxt;  
         if(nxt)  
           nxt = nxt->next;   
       }  
     }  
     return newHead;  
   }