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].
class Solution:
def flipLights(self, n, m):
"""
:type n: int
:type m: int
:rtype: int
"""
n = min(n, 3)
if m == 0: return 1
if m == 1: return [2, 3, 4][n-1]
if m == 2: return [2, 4, 7][n-1]
return [2, 4, 8][n-1]