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How to Solve Bulb Switcher II Problem
Master the Bulb Switcher II LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.
Phantom Code generates complete solutions and debugging hints that you can use while explaining your approach, so you stay calm and in control.
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Start Free for WindowsMedium#672
LeetCode ProblemBulb Switcher II
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: 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.
MathBit ManipulationDepth-First SearchBreadth-First Search
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Problem Breakdown
Understanding the Bulb Switcher II Problem
Let's break down this LeetCode problem and understand what makes it challenging in interview settings.
Problem Statement
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: 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.
MediumProblem #672
LeetCodeBulb Switcher II
Related Topics
MathBit ManipulationDepth-First SearchBreadth-First Search
How Phantom Code Helps
Get real-time assistance for Bulb Switcher II problems during coding interviews. Phantom Code provides instant solutions and explanations.
Examples
# Example 1
Input
n = 1, presses = 1
Output
2
# Example 2
Input
n = 2, presses = 1
Output
3
# Example 3
Input
n = 3, presses = 1
Output
4
Constraints
1 <= n <= 1000
0 <= presses <= 1000
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Solve Bulb Switcher II — There is a room with n bulbs labeled from 1 to n that all are turned on initiall...
Here's the optimal approach using Math:
def solve(input):
# Optimal O(n) solution
return result
Time: O(n) | Space: O(n)
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Frequently Asked Questions
Common questions about solving Bulb Switcher II and using Phantom Code during coding interviews.
How does Phantom Code help me solve coding problems like Bulb Switcher II during interviews?
Phantom Code generates complete solutions instantly with proper complexity analysis, letting you focus on explaining your approach and demonstrating problem-solving skills rather than getting stuck on implementation details during high-pressure situations.
What if the interviewer asks follow-up questions or modifications to problems like Bulb Switcher II?
Phantom Code adapts in real-time. Screenshot the modified problem or use audio mode to capture the interviewer's follow-up, and get an updated solution within seconds — including edge cases and optimizations.
Can Phantom Code help me communicate my solution for problems like Bulb Switcher II?
Yes. Phantom Code provides step-by-step approach explanations with 3 progressive thoughts, so you can walk through your solution naturally. It also provides time and space complexity analysis to discuss trade-offs.
How does Phantom Code assist with different programming languages for Bulb Switcher II type problems?
Phantom Code supports 11 programming languages including Python, Java, C++, JavaScript, TypeScript, Go, Rust, Ruby, Swift, Kotlin, and C#. Set your preferred language and get idiomatic solutions.
What coding mistakes does Phantom Code help me avoid during Bulb Switcher II interviews?
Phantom Code catches common mistakes like off-by-one errors, missing edge cases, incorrect base conditions, and suboptimal approaches. It provides clean, well-structured code that handles all edge cases.
Is Phantom Code detectable when solving problems like Bulb Switcher II during live interviews?
No. Phantom Code runs as an invisible desktop overlay that doesn't appear in screen shares, recordings, or proctoring software. It works with Zoom, HackerRank, CodeSignal, CoderPad, and all major platforms.
How does Phantom Code help when I'm struggling with Bulb Switcher II style questions under pressure?
The AI provides structured guidance: first the approach (what algorithm/data structure to use and why), then the implementation with clean code, and finally complexity analysis. This helps you think clearly even under pressure.
Does Phantom Code work for the coding platforms used in Bulb Switcher II interviews?
Yes. Phantom Code works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.
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