Infection Spread on a Grid (Cellular Automaton)
Company: Google
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: hard
Interview Round: Technical Screen
Overview: This question tests a candidate's ability to implement and optimize a synchronous cellular automaton simulation on a 2D grid, assessing proficiency in BFS-based propagation, state machine design, and incremental computation. It falls under algorithms and grid simulation, evaluating practical coding skill and the ability to handle progressively complex constraints including recovery delays, barriers, and early-termination fixed-point detection.