Delete Nodes and Return Forest: Python Interview with a Google Engineer

REPLAY EPISODE: In this Google coding interview mock, a candidate tackles one of the trickiest binary tree problems that keeps showing up in real interviews.

🧩 Problem: Given the root of a binary tree and a list of node values to delete, remove those nodes and return the roots of all remaining subtrees. (LeetCode #1110 – Delete Nodes and Return Forest)

Watch how the candidate breaks it down from scratch:

✅ Clarifies the problem and edge cases like a real Google interview

✅ Designs an O(n) BFS solution (with clean logic)

✅ Codes in Python and tests multiple tricky examples

✅ Gets detailed interviewer feedback on problem-solving, communication, and structure

💡 What you’ll learn:

• How to think out loud in a Google interview

• BFS vs DFS strategies for tree deletion problems

• How to handle “delete and return forest”–type graph problems

• What great communication looks like under pressure

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