The Level Inspector
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
- L4
Interview Prompt
You're handed a binary tree decoded from a nested-dict export: each node is a dict with an int `val` plus `left` and `right` children that are either another such node or `None`. Group the values by depth, returning a list whose entry at index i holds every value at depth i in left-to-right order, with the root sitting at depth 0. An empty tree, where `root` is `None`, comes back as an empty list.
Summary
Each floor of the tower tells a different story.
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