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How to Solve LRU Cache Problem

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

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Medium#146
LeetCode Problem

LRU Cache

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache. Implement the LRUCache class: The functions get and put must each run in O(1) average time complexity.

Hash TableLinked ListDesignDoubly-Linked List

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Problem Breakdown

Understanding the LRU Cache Problem

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

Problem Statement

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache. Implement the LRUCache class: The functions get and put must each run in O(1) average time complexity.

MediumProblem #146
LeetCode

LRU Cache

Related Topics

Hash TableLinked ListDesignDoubly-Linked List

How PhantomCodeAI Helps

Get real-time assistance for LRU Cache problems during coding interviews. PhantomCodeAI provides instant solutions and explanations.

Examples

# Example 1

Input
—
Output
—

Constraints

1 <= capacity <= 3000
0 <= key <= 104
0 <= value <= 105
At most 2 * 105 calls will be made to get and put.

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Solve LRU Cache — Design a data structure that follows the constraints of a Least Recently Used (L...

Here's the optimal approach using Hash Table:

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
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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 LRU Cache 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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