【LeetCode】 082. Remove Duplicates from Sorted List II

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,
Given 1->2->3->3->4->4->5, return 1->2->5.
Given 1->1->1->2->3, return 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) {        ListNode dummy = new ListNode(0);        dummy.next = head;        ListNode prev = dummy, curr = head;        while (curr != null) {            while (curr.next != null && curr.val == curr.next.val) {                curr = curr.next;            }            if (prev.next == curr) {                prev = prev.next;            } else {                prev.next = curr.next;            }            curr = curr.next;        }        return dummy.next;    }}