Koko Eating Bananas

You are given an integer array piles where piles[i] is the number of bananas in the ith pile. You are also given an integer h, which represents the number of hours you have to eat all the bananas.

You may choose a bananas-per-hour eating rate of k. Each hour, you may choose a single pile and eat up to k bananas from it. If the pile has fewer than k bananas, you finish the pile but may not eat from another pile in the same hour. ...