Find minimal time to serve customers
Company: Pinterest
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Onsite
You manage a bank with k tellers; teller i takes serviceTimes[i] minutes to serve one customer and works continuously. Given an integer array serviceTimes and an integer m (customers to serve), return the minimum integer time T such that sum over i of floor(T / serviceTimes[i]) >= m. Describe your algorithm, prove correctness, analyze time/space complexity, and implement it. Discuss edge cases (very large m, slow tellers, identical rates).
Quick Answer: This question evaluates algorithm design and mathematical reasoning for rate-based scheduling, including aggregate capacity computation, integer arithmetic, correctness proof, and analysis of edge cases.