【leetcode】Remove Duplicates from Sorted List

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. * public class ListNode { *     int val; *     ListNode next; *     ListNode(int x) { val = x; } * } */public class Solution {    public ListNode deleteDuplicates(ListNode head) {        if(head==null||head.next==null)        return head;                ListNode list=head;        while(list.next!=null){            if(list.val==list.next.val){                list.next=list.next.next;            }            else{                list=list.next;            }        }        return head;    }}