LeetCode (Remove Duplicates from Sorted List)

Problem:

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.

Solution:

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    ListNode* deleteDuplicates(ListNode* head) {        if(!head || !head->next) return head;        if(head->val == head->next->val)            return deleteDuplicates(head->next);        else{            head->next = deleteDuplicates(head->next);            return head;        }    }};