Grid Gravity and Removal / Candy Crush

Problem Overview

You are given an m×n grid where each cell contains a digit 0–9. The problem has two phases: Phase 1 – Match Detection: Identify all horizontal and vertical runs of 3 or more consecutive identical digits. For each match, record it as [position, length] (or (value, count) pair). Output order:…

• 3 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