LeetCode Remove Duplicates from Sorted List

题目：

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.

/** * 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) {        ListNode *cur = head;        while(cur != NULL && cur->next != NULL) {            if(cur->val == cur->next->val)                cur->next = cur->next->next;            else                cur = cur->next;        }        return head;    }};