import java.util.*; /* * public class ListNode { * int val; * ListNode next = null; * } */ public class Solution { /** * * @param head ListNode类 * @return ListNode类 */ public ListNode deleteDuplicates (ListNode head) { if (head == null) { return head; } ListNode headNode = new ListNode(-1); headNode.next = head; ListNode preNode = headNode; ListNode curNode = head; while (curNode != null && curNode.next != null) { if (curNode.val == curNode.next.val) { while (curNode.next != null && curNode.val == curNode.next.val) { curNode = curNode.next; } preNode.next = curNode.next; curNode = curNode.next; } else { preNode = curNode; curNode = curNode.next; } } return headNode.next; } }