René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"有赞\u0026leetcode141：判断一个单链表是否有环","articleBody":"给定一个链表，判断链表中是否有环。\r\n\r\n为了表示给定链表中的环，我们使用整数 `pos` 来表示链表尾连接到链表中的位置（索引从 `0` 开始）。 如果 `pos` 是 `-1`，则在该链表中没有环。\r\n\r\n**示例 1：**\r\n\r\n```js\r\n输入：head = [3,2,0,-4], pos = 1\r\n输出：true\r\n解释：链表中有一个环，其尾部连接到第二个节点。\r\n```\r\n\r\n![](http://resource.muyiy.cn/image/20200409215648.png)\r\n\r\n\r\n**示例 2：**\r\n\r\n```js\r\n输入：head = [1,2], pos = 0\r\n输出：true\r\n解释：链表中有一个环，其尾部连接到第一个节点。\r\n```\r\n\r\n![](http://resource.muyiy.cn/image/20200409215701.png)\r\n\r\n**示例 3：**\r\n\r\n```js\r\n输入：head = [1], pos = -1\r\n输出：false\r\n解释：链表中没有环。\r\n```\r\n\r\n![](http://resource.muyiy.cn/image/20200409215712.png)\r\n\r\n\r\n**进阶：**\r\n\r\n你能用 O(1)（即，常量）内存解决此问题吗？\r\n\r\n附leetcode地址：[leetcode](https://leetcode-cn.com/problems/linked-list-cycle/solution/pan-duan-yi-ge-dan-lian-biao-shi-fou-you-huan-by-u/)","author":{"url":"https://github.com/sisterAn","@type":"Person","name":"sisterAn"},"datePublished":"2020-04-09T14:42:51.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/13/JavaScript-Algorithms/issues/13"}