Maximum Substrings

Problem Overview

• Replace each '.' in the string with a lowercase letter to maximize the total number of beautiful substrings (all characters identical), and return that maximum.
• Input: string color (length 1–5000) with '.' for white/unassigned; Output: integer count; substrings are contiguous.
• Context: Parade uniforms in HackerLand where no white uniforms are allowed.
• From Snowflake interviews; a coding interview problem and interview question focused on maximizing substrings.