Package g0601_0700.s0672_bulb_switcher_ii

Class 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 Detail

      • Solution

        public Solution()

    • Method Detail

      • flipLights

        public int flipLights​(int n,
                      int m)