链表中环的入口结点 牛客网 剑指Offer
题目描述给一个链表，若其中包含环，请找出该链表的环的入口结点，否则，输出null。 # class ListNode: # def __init__(self, x): # self.val = x # self.next = None class Solution: def EntryNodeOfLoop(self, pHead): if pHead == None: return None pSlow = pHead.next if pSlow == None: return None pFast = pSlow.next while pFast: if pSlow == pFast: break pSlow = pSlow.next pFast = pFast.next if pFast: pFast = pFast.next NodeLoop = 1 flagNode = pSlow while flagNode.next != pSlow: NodeLoop += 1 flagNode = flagNode.next pFirst = pHead for i in range(NodeLoop): pFirst = pFirst.next pSecond = pHead while pFirst != pSecond: pFirst = pFirst.next pSecond = pSecond.next return pFirst
转载于:https://www.cnblogs.com/vercont/p/10210349.html
