【LeetCode】672. Bulb Switcher II 解题报告（Python）

【LeetCode】672. Bulb Switcher II 解题报告（Python）

标签（空格分隔）： LeetCode

题目地址：https://leetcode.com/problems/bulb-switcher-ii/description/

题目描述：

There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing exactly m unknown operations towards buttons, you need to return how many different kinds of status of the n lights could be.

Suppose n lights are labeled as number [1, 2, 3 …, n], function of these 4 buttons are given below:

Flip all the lights.

Flip lights with even numbers.

Flip lights with odd numbers.

Flip lights with (3k + 1) numbers, k = 0, 1, 2, …

Example 1:
Input: n = 1, m = 1.
Output: 2
Explanation: Status can be: [on], [off]
Example 2:
Input: n = 2, m = 1.
Output: 3
Explanation: Status can be: [on, off], [off, on], [off, off]
Example 3:
Input: n = 3, m = 1.
Output: 4
Explanation: Status can be: [off, on, off], [on, off, on], [off, off, off], [off, on, on].

Note: n and m both fit in range [0, 1000].

题目大意

有四种操作。分别对灯进行变换。。不是一个数学题，这个是脑筋急转弯。

解题方法

额，不会做。脑子不够用。。

可以看http://blog.csdn.net/huanghanqian/article/details/77857912

代码：

class Solution:
def flipLights(self, n, m):
"""
:type n: int
:type m: int
:rtype: int
"""
if m == 0:
return 1
if n >= 3:
return 4 if m == 1 else 7 if m == 2 else 8
if n == 2:
return 3 if m == 1 else 4
if n == 1:
return 2

日期

2018 年 3 月 5 日