leetcode 141 142. Linked List Cycle

【leetcode 141 142. Linked List Cycle】的更多相关文章

[LeetCode] 141&142 Linked List Cycle I & II

Problem: Given a linked list, determine if it has a cycle in it. Follow up:Can you solve it without using extra space? https://oj.leetcode.com/problems/linked-list-cycle/ Problem II: Given a linked list, return the node where the cycle begins. If the…

leetcode 141 142. Linked List Cycle

题目描述: 不用辅助空间判断,链表中是否有环 /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ /*一个指针走的快一个指针走得慢*/ class Solution { public: bool hasCycle(ListNode *head) { if(head ==…

【LeetCode】142. Linked List Cycle II

Difficulty:medium More:[目录]LeetCode Java实现 Description Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Note: Do not modify the linked list. Follow up:Can you solve it without using extra space? Intuiti…

【LeetCode】142. Linked List Cycle II (2 solutions)

Linked List Cycle II Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Follow up:Can you solve it without using extra space? 解法一: 使用unordered_map记录当前节点是否被访问过,如访问过返回该节点,如到达尾部说明无环. /** * Definition for sing…

<LeetCode OJ> 141 / 142 Linked List Cycle（I / II）

Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 分析: 假设有环?遍历链表将无法走完,假设无环终会走到尾为NULL的位置让一个指针每次走一个,一个指针每次走两个位置. 假设当中一个为NULL则无环. 假设相遇(必会相遇)了则有环. time,o(n),space,o(1) /** * Definition for sing…

【LeetCode】142. Linked List Cycle II 解题报告（Python & C++）

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录题目描述题目大意解题方法双指针 set 日期题目地址:https://leetcode.com/problems/linked-list-cycle-ii/description/ 题目描述 Given a linked list, return the node where the cycle begins. If there is no cycle, return n…

LeetCode OJ 142. Linked List Cycle II

Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Note: Do not modify the linked list. Follow up:Can you solve it without using extra space? 这个题还是蛮考验数学推理的,不过在前一个题的基础上还是能推出结果的.这是英文一段解释,非常有帮助. First Step: A…