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How to Solve Design Front Middle Back Queue Problem

Master the Design Front Middle Back Queue LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.

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Medium#1670

LeetCode Problem

Design Front Middle Back Queue

Design a queue that supports push and pop operations in the front, middle, and back. Implement the FrontMiddleBack class: Notice that when there are two middle position choices, the operation is performed on the frontmost middle position choice. For example:

ArrayLinked ListDesignQueueData Stream

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Problem Breakdown

Understanding the Design Front Middle Back Queue Problem

Let's break down this LeetCode problem and understand what makes it challenging in interview settings.

Problem Statement

MediumProblem #1670

LeetCode

Design Front Middle Back Queue

How Phantom Code Helps

Get real-time assistance for Design Front Middle Back Queue problems during coding interviews. Phantom Code provides instant solutions and explanations.

Examples

# Example 1

Input

["FrontMiddleBackQueue", "pushFront", "pushBack", "pushMiddle", "pushMiddle", "popFront", "popMiddle", "popMiddle", "popBack", "popFront"] [[], [1], [2], [3], [4], [], [], [], [], []]

Output

[null, null, null, null, null, 1, 3, 4, 2, -1]

Constraints

1 <= val <= 109

At most 1000 calls will be made to pushFront, pushMiddle, pushBack, popFront, popMiddle, and popBack.

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Solve Design Front Middle Back Queue — Design a queue that supports push and pop operations in the front, middle, and b...

Here's the optimal approach using Array:

def solve(input):

# Optimal O(n) solution

return result

Time: O(n) | Space: O(n)

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Undetectability Checklist

Run compatibility test before interviews

Use recommended Zoom version settings

Enable advanced screen capture options

Verify native desktop architecture

Test with screen recording software

Platform Compatibility

Zoom

Supported

Google Meet

Supported

HackerRank

Supported

CodeSignal

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CoderPad

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Teams

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Undetectability and technical details

Our native desktop architecture avoids common detection vectors used by browser extensions. We provide a clear checklist so you can run basic checks and confirm the app will be invisible.

Platform compatibility and limitations

We work with Zoom, HackerRank, CodeSignal, CoderPad and other web-based platforms. Check the compatibility note and request a browser link if a specific desktop app is unsupported.

Frequently Asked Questions

Common questions about solving Design Front Middle Back Queue and using Phantom Code during coding interviews.

How does Phantom Code help me solve coding problems like Design Front Middle Back Queue 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 Design Front Middle Back Queue?

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 Design Front Middle Back Queue?

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 Design Front Middle Back Queue 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 Design Front Middle Back Queue 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 Design Front Middle Back Queue 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 Design Front Middle Back Queue 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 Design Front Middle Back Queue 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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