python3 环形链表求解

# -*- coding:utf-8 -*-
class Node():
    def __init__(self, x):
        self.val = x
        self.next = None

class Solution:
    def LastRemaining_Solution(self, n, m):
        # write code here
        if not n:
            return -1
        kids = [i for i in range(1, n)]
        root = Node(0)
        copy_root = root
        for i in kids:
            root.next = Node(i)
            root = root.next
        root.next = copy_root  # 组建环形链表成功
        if m == 1:
            return root.val
        for i in range(n - 1):
            for j in range(m - 1):
                root = root.next
            root.next = root.next.next
        return root.val