Disease/Epidemic Spreading Simulation

Problem Overview

You are given an M×N 2D grid representing a field of plants. Each cell is one of: 'X' (infected), '.' (healthy/susceptible), or 'I' (immune). The problem is presented as 5 progressive sub-parts, each adding complexity: Part 1 (Basic Infection): Every day, each infected cell ('X') spreads infection to all 8…

• 6 candidate-reported follow-ups — the exact probes interviewers asked, with the trigger for each
• The rest of the problem statement — full requirements, constraints, and edge cases
• Approach and trade-offs — what passing candidates did, and the mistakes that sink people