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:
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].