本文实例讲述了Python3实现的判断环形链表算法。分享给大家供大家参考，具体如下：
给定一个链表，判断链表中是否有环。
方案一：快慢指针遍历，若出现相等的情况，说明有环
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# Definition for singly-linked list.# class ListNode(object):# def __init__(self, x):# self.val = x# self.next = Noneclass Solution(object): def hasCycle(self, head): """ :type head: ListNode :rtype: bool """ slow = fast = head while fast and fast.next: slow = slow.next fast = fast.next.next if fast == slow: return True return False |
方案二：遍历链表，寻找.next=head的元素。 但超出时间限制
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# Definition for singly-linked list.# class ListNode(object):# def __init__(self, x):# self.val = x# self.next = Noneclass Solution(object): def hasCycle(self, head): """ :type head: ListNode :rtype: bool """ if not head: return False cur = head.next while cur: if cur.next == head: return True cur = cur.next return False |
希望本文所述对大家Python程序设计有所帮助。
原文链接：https://blog.csdn.net/zhenghaitian/article/details/81025412
