leetcode JAVA Remove Duplicates from Sorted List II 难度系数3 3.29

yundomo

于 2014-02-01 11:36:25 发布

阅读量1.2k

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/yiding_he/article/details/18893627

leetcode java 150 专栏收录该内容

86 篇文章

订阅专栏

本文介绍了一种算法，用于从已排序的链表中移除所有重复出现的节点，仅保留原始列表中的唯一数值。通过示例展示了操作过程及预期结果。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Question：

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;
 *         next = null;
 *     }
 * }
 */
public class Solution {
   public ListNode deleteDuplicates(ListNode head) {
		if (head == null || head.next == null)
			return head;
		ListNode backhead = new ListNode(0);
		backhead.next = head;
		ListNode pre = backhead;
		ListNode cur = head;
		ListNode nex = head.next;
		boolean delstate = false;
		while (nex != null) {
			if (nex.val == cur.val) {
				delstate = true;
			} else {
				if (delstate) {
					pre.next = nex;
					delstate = false;
				} else {
					pre = cur;
				}
			}
			cur = nex;
			nex = nex.next;
		}
		if(delstate)
			pre.next = null;
		return backhead.next;
	}
}