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The Hierarchy Builder
A hard Python mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Python
- Difficulty
- hard
- Seniority
- senior
Interview Prompt
The org chart is stored as flat parent-child pairs in a database export, and the frontend needs it as a nested JSON tree for the visualization component. Write a function that converts a flat list of (parent, child) tuples into a nested dictionary. There is exactly one root node (a parent that never appears as a child). Leaf nodes map to empty dicts. No cycles exist in the data.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your python solution with real code execution
- Get instant feedback and a hire/no-hire decision