[LeetCode][JavaScript]Remove Duplicates from Sorted List II

 1 /**
 2  * Definition for singly-linked list.
 3  * function ListNode(val) {
 4  *     this.val = val;
 5  *     this.next = null;
 6  * }
 7  */
 8 /**
 9  * @param {ListNode} head
10  * @return {ListNode}
11  */
12 var deleteDuplicates = function(head) {
13     if(!head || !head.next){
14         return head;
15     }
16     
17     if(head.val === head.next.val){
18         var value = head.val;
19         while(head && head.val === value){
20             head = head.next;
21         }
22         return deleteDuplicates(head);
23     }else{
24         var h = head;
25         head = deleteDuplicates(head.next);
26         h.next = head;
27         return h;
28     }
29 };