题解 | 输出单向链表中倒数第k个结点

class Node:
    def __init__(self,val):
        self.val=val
        self.next=None
    def setNext(self,newnext):
        self.next=newnext
    def getNext(self):
        return self.next
class Unorderedlist:
    def  __init__(self):
        self.head=None
    def isEmpty(self):
        return self.head == None
    def add(self,item):
        temp = Node(item)
        temp.setNext(self.head)
        self.head=temp
    def pos_search(self,pos):
        count=0
        item=self.head
        while item!=None:
            count+=1
            if count!=N-pos+1:
                item=item.next
            else:
                return item.val
while True:
    try:
        N,lst_1,k=int(input()),input().split()[::-1],int(input())
        un_lst=Unorderedlist()
        for i in range(N):
            n=lst_1[i]
            un_lst.add(n)
        a=un_lst.pos_search(k)
        print(a)
    except:
        break