Given a sorted linked list, delete all duplicates such that each element appear onlyonce.

For example,
Given1->1->2, return1->2.
Given1->1->2->3->3, return1->2->3.

tag: linkedlist

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
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;
    }
}