Remove Duplicates from Sorted List

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

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

思路： 去重复，cur, node即可；

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        ListNode dummpy = new ListNode(-1);
        dummpy.next = head;
        ListNode cur = head;
        while(cur != null) {
            ListNode curnext = cur.next;
            if(curnext != null && cur.val == curnext.val) {
                cur.next = curnext.next;
            } else {
                cur = curnext;
            }
        }
        return dummpy.next;
    }
}