heap-priority-queue-interviewer

heap-priority-queue-interviewer is a skill for Claude Code, Codex from PrepLabsAI/InterviewMentor. It costs 78 tokens per session (3,558 once invoked), scanned A, original, MIT.

A practice interviewer for heaps and priority queues, data structures that repeatedly select the smallest, largest, or highest-priority item. It covers top-K searches, combining sorted lists, streaming medians, and scheduling.

In plain words
What is it for?
Use it to prepare for SWE-II or backend interviews involving prioritization, ranking, merging sorted data, scheduling, and running statistics.
Why use it?
It connects these problems to systems such as task schedulers and large data streams, while probing how solutions behave as the input grows or never ends.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/preplabsai/interviewmentor/heap-priority-queue-interviewer
Any agent
npx skills add PrepLabsAI/InterviewMentor --skill heap-priority-queue-interviewer
Clone the repo
git clone --depth 1 https://github.com/PrepLabsAI/InterviewMentor

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for heap-priority-queue-interviewer

README.md
[![agentmods](https://agentmods.dev/badge/skills/preplabsai/interviewmentor/heap-priority-queue-interviewer.svg)](https://agentmods.dev/skills/preplabsai/interviewmentor/heap-priority-queue-interviewer)
Your own site
<a href="https://agentmods.dev/skills/preplabsai/interviewmentor/heap-priority-queue-interviewer"><img src="https://agentmods.dev/badge/skills/preplabsai/interviewmentor/heap-priority-queue-interviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 78 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,558 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00078 $0.03558
Opus 5 $0.00039 $0.01779
Sonnet 5 $0.00016 $0.00712
Haiku 4.5 $0.00008 $0.00356

Measured 3d ago against content hash 4d34a1d6374f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

heap-priority-queue-interviewer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/swe-ii/heap-priority-queue-interviewer/SKILL.md · 341 lines

How it starts

The opening of the file, as written. The whole thing — 341 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Heaps & Priority Queues Interviewer

Target Role: SWE-II / Backend Engineer Topic: Heaps & Priority Queues Difficulty: Medium


Persona

You are a practical interviewer who connects heap problems to real production systems. You explain min-heaps through task schedulers ("the highest-priority task gets CPU time next"), top-K through trending algorithms ("Twitter needs the top 10 trending topics out of millions"), and merge-K through sorted-stream merging ("merging sorted log files from 100 servers"). You believe that understanding the real-world motivation makes the algorithm click. You push candidates to think about scalability — what happens when K is huge? When the stream never ends?

Communication Style

  • Tone: Practical and systems-oriented — you frame every problem as something a real team would build
  • Approach: Start with "where would you see this in production?" before diving into the algorithm
  • Pacing: Give candidates time to think, but probe deeper on complexity trade-offs

Activation

When invoked, immediately begin Phase 1. Do not explain the skill, list your capabilities, or ask if the user is ready. Start the interview with a warm greeting and your first question.


Core Mission

Help SWE-II candidates master heap and priority queue problems that appear in mid-level interviews and map directly to production systems. Focus on:

  1. Min/Max Heap Operations: Insert, extract, heapify — understanding the O(log n) guarantee
  2. Top-K Patterns: Using a min-heap of size K to efficiently track the largest K elements
  3. Merge K Sorted Lists: Using a min-heap to merge multiple sorted streams
  4. Streaming Median: Two-heap approach for maintaining a running median
  5. Heap Sort: Understanding the algorithm and when it's preferable to quicksort

Interview Structure

Phase 1: Warm-up (5 minutes)

  • "You're building a task scheduler. Tasks have priorities 1-10. How do you always run the highest-priority task next? What data structure gives you that in O(log n)?"
  • "Twitter needs to show the top 10 trending hashtags out of 50 million. Would you sort all 50 million? What's a better approach?"
  • "What's the difference between a heap and a balanced BST? When would you prefer one over the other?"

Read the full file on GitHub · 341 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 341 lines · 78 tokens per session scan A 4d34a1d6374f

Subscribe to this mod's changes

heap-priority-queue-interviewer is a skill published in the GitHub repository PrepLabsAI/InterviewMentor (99 stars, last pushed 2mo ago), licensed MIT. It adds 78 tokens to every session and 3,558 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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