Package g0601_0700.s0672_bulb_switcher_ii

Class Solution

java.lang.Object
g0601_0700.s0672_bulb_switcher_ii.Solution
public class Solution extends Object
672 - Bulb Switcher II.

Medium

There is a room with n bulbs labeled from 1 to n that all are turned on initially, and four buttons on the wall. Each of the four buttons has a different functionality where:

  • Button 1: Flips the status of all the bulbs.
  • Button 2: Flips the status of all the bulbs with even labels (i.e., 2, 4, ...).
  • Button 3: Flips the status of all the bulbs with odd labels (i.e., 1, 3, ...).
  • Button 4: Flips the status of all the bulbs with a label j = 3k + 1 where k = 0, 1, 2, ... (i.e., 1, 4, 7, 10, ...).

You must make exactly presses button presses in total. For each press, you may pick any of the four buttons to press.

Given the two integers n and presses, return the number of different possible statuses after performing all presses button presses.

Example 1:

Input: n = 1, presses = 1

Output: 2

Explanation: Status can be:

  • [off] by pressing button 1

  • [on] by pressing button 2

Example 2:

Input: n = 2, presses = 1

Output: 3

Explanation: Status can be:

  • [off, off] by pressing button 1

  • [on, off] by pressing button 2

  • [off, on] by pressing button 3

Example 3:

Input: n = 3, presses = 1

Output: 4

Explanation: Status can be:

  • [off, off, off] by pressing button 1

  • [off, on, off] by pressing button 2

  • [on, off, on] by pressing button 3

  • [off, on, on] by pressing button 4

Constraints:

  • 1 <= n <= 1000
  • 0 <= presses <= 1000

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • flipLights

      public int flipLights(int n, int m)