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

.

移除有序链表里面的重复元素，2个指针来移动判断即可。

代码如下：

/**
* 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) return head;
ListNode cur = head;
ListNode after = head;

while(after!=null){
after = after.next;
while(after !=null && after.val==cur.val){
after = after.next;
}
cur.next = after;
cur = after;
}
return head;
}
}