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How to Solve Longest Common Prefix Problem

Master the Longest Common Prefix LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.

PhantomCodeAI 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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Easy#14
LeetCode Problem

Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "".

ArrayStringTrie

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Problem Breakdown

Understanding the Longest Common Prefix Problem

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

Problem Statement

Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "".

EasyProblem #14
LeetCode

Longest Common Prefix

Related Topics

ArrayStringTrie

How PhantomCodeAI Helps

Get real-time assistance for Longest Common Prefix problems during coding interviews. PhantomCodeAI provides instant solutions and explanations.

Examples

# Example 1

Input
strs = ["flower","flow","flight"]
Output
"fl"

# Example 2

Input
strs = ["dog","racecar","car"]
Output
""

Constraints

1 <= strs.length <= 200
0 <= strs[i].length <= 200
strs[i] consists of only lowercase English letters if it is non-empty.

How PhantomCodeAI Helps with LeetCode Problems

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See PhantomCodeAI in Action

Watch how PhantomCodeAI helps solve LeetCode problems during live interviews

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Solve Longest Common Prefix — Write a function to find the longest common prefix string amongst an array of st...

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
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HackerRank
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CodeSignal
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CoderPad
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Teams
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User results and traction

Thousands of developers use PhantomCodeAI. Social proof signals that this approach helps real candidates land offers across a range of companies.

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 Longest Common Prefix and using PhantomCodeAI during coding interviews.

How does PhantomCodeAI help with LeetCode problems during a coding interview?
PhantomCodeAI reads the problem from a screenshot or listens to it via audio, then generates a complete solution with a step-by-step approach and time/space complexity, so you can focus on explaining your reasoning rather than getting stuck on implementation.
Which programming languages does PhantomCodeAI support?
11 languages including Python, Java, C++, JavaScript, TypeScript, Go, Rust, Ruby, Swift, Kotlin, and C#. Set a preferred language to get idiomatic solutions.
Does PhantomCodeAI work with HackerRank, CodeSignal, and CoderPad?
Yes — it works alongside LeetCode, HackerRank, CodeSignal, CoderPad, and HackerEarth, plus any browser-based coding environment.
Can PhantomCodeAI handle follow-up questions and modifications?
Yes. Capture the modified problem by screenshot or audio and get an updated solution within seconds, including new edge cases and optimizations.
Is PhantomCodeAI detectable during live interviews?
PhantomCodeAI runs as a native desktop overlay that does not appear in screen shares, recordings, or proctoring software, and works with Zoom, Google Meet, Microsoft Teams, and major coding platforms.
Should I still practice these problems on my own first?
Yes. The most durable preparation is solving problems unaided first, then using AI afterward to review your approach, complexity, and missed edge cases — use it to debrief and learn, not to skip the reps.

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