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The Cycle Detector

A medium Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.

Domain
Python
Difficulty
medium
Seniority
L3

Interview Prompt

Given a list where each index i has next_pointers[i] = next index (or -1 for tail), return True if starting from any index leads to a cycle. Actually: follow starting from index 0 and detect whether any index is revisited before hitting -1 or out-of-range.

Summary

Follow the chain long enough and you might end up where you started.

How This Interview Works

  1. Read the vague prompt (just like a real interview)
  2. Ask clarifying questions to the AI interviewer
  3. Write your python solution with real code execution
  4. Get instant feedback and a hire/no-hire decision

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