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How to Solve Maximum Sum of an Hourglass Problem

Master the Maximum Sum of an Hourglass 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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Medium#2428

LeetCode Problem

Maximum Sum of an Hourglass

You are given an m x n integer matrix grid. We define an hourglass as a part of the matrix with the following form: Return the maximum sum of the elements of an hourglass. Note that an hourglass cannot be rotated and must be entirely contained within the matrix.

ArrayMatrixPrefix Sum

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Problem Breakdown

Understanding the Maximum Sum of an Hourglass Problem

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

Problem Statement

MediumProblem #2428

LeetCode

Maximum Sum of an Hourglass

How Phantom Code Helps

Get real-time assistance for Maximum Sum of an Hourglass problems during coding interviews. Phantom Code provides instant solutions and explanations.

Examples

# Example 1

Input

grid = [[6,2,1,3],[4,2,1,5],[9,2,8,7],[4,1,2,9]]

Output

# Example 2

Input

grid = [[1,2,3],[4,5,6],[7,8,9]]

Output

Constraints

m == grid.length

n == grid[i].length

3 <= m, n <= 150

0 <= grid[i][j] <= 106

How Phantom Code Helps with LeetCode Problems

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Solve Maximum Sum of an Hourglass — You are given an m x n integer matrix grid. We define an hourglass as a part of ...

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

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Platform Compatibility

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Google Meet

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HackerRank

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CodeSignal

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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 Maximum Sum of an Hourglass and using Phantom Code during coding interviews.

How does Phantom Code help me solve coding problems like Maximum Sum of an Hourglass 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 Maximum Sum of an Hourglass?

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 Maximum Sum of an Hourglass?

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 Maximum Sum of an Hourglass 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 Maximum Sum of an Hourglass 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 Maximum Sum of an Hourglass 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 Maximum Sum of an Hourglass 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 Maximum Sum of an Hourglass 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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