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#672 - Bulb Switcher II
Problem Description
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.
Solution
/**
* @param {number} n
* @param {number} presses
* @return {number}
*/
var flipLights = function(n, presses) {
if (presses === 0) return 1;
if (n === 1) return presses >= 1 ? 2 : 1;
if (n === 2) return presses === 1 ? 3 : 4;
if (presses === 1) return 4;
if (presses === 2) return 7;
return 8;
};