Find Minimum Idleness

Problem Overview

• Given a shader string of 'a'/'b' for two GPUs, find the minimum idleness, defined as the longest consecutive use of the same GPU.
• You may flip up to switchCount characters ('a'↔'b') to reduce that maximum run.
• Input: String shader, int switchCount; Output: int minimum achievable idleness.
• Context: game rendering and dual-GPU scheduling.
• From Salesforce interviews; a coding interview problem and common interview question.