Navigating Google's Software Engineer Interview: Mastering the Binary Search Tree Iterator II

google | Software Engineer | Interview Experience

Interview Date: Not specified
Result: Pass
Difficulty: Average

Interview Process

The interview consisted of a technical phone screen focused on coding. The candidate was asked to solve a problem involving a binary tree.

Technical Questions

  1. Binary Tree Level Order Traversal Iterator
    • Topic: Tree, Breadth-First Search, Design
    • Question: Implement an iterator that returns the level order traversal of a binary tree without storing the entire traversal in memory at once. The candidate proposed using a queue to maintain the current level’s nodes and flatten the next level as needed.

Tips & Insights

  • The candidate emphasized the importance of memory efficiency when designing an iterator and suggested that each iterator should maintain its own queue while the underlying tree remains read-only. They also mentioned using lightweight locks or version snapshots to avoid conflicts when multiple iterators share the same tree structure.