TikTok Balanced Clips

Problem Overview

• Compute the number of smooth lowercase clips of length clipLength where adjacent letters differ by at most diff.
• Input: clipLength (2–1e5) and diff (1–25); Output: total count modulo 1e9+7.
• Real-world context: TikTok clip generation with constraints on neighboring character differences.
• From TikTok interviews; a coding interview question and counting problem.