【Leetcode】Given a non-empty, singly linked list with head node head, return a middle node of link...
Givenanon-empty,singlylinkedlistwithheadnodehead,returnamiddlenodeoflinkedlist.Iftherearetwomiddlenodes,returnthesecondmiddlenode.classSolution:defmiddleNode(self,head):""":typehead:ListNode:rtype:Lis