给定一个排序链表，删除所有含有重复数字的节点，只保留原始链表中 没有重复出现 的数字。
示例 1:
代码语言：javascript复制输入: 1->2->3->3->4->4->5
输出: 1->2->5示例 2:
代码语言：javascript复制输入: 1->1->1->2->3
输出: 2->3解：
代码语言：javascript复制/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode deleteDuplicates(ListNode head) {
if (head == null) {
return head;
}
ListNode newhead = new ListNode(-1);
ListNode tmp = newhead;
while (head != null && head.next != null) {
if (head.val == head.next.val) {
while (head.next != null && head.val == head.next.val) {
head = head.next;
}
head = head.next;
} else {
tmp.next = head;
tmp = tmp.next;
head = head.next;
}
}
tmp.next = head;
return newhead.next;
}
}
