Koko Eating Bananas

Problem

Koko loves to eat bananas. There are n piles of bananas, the i-th pile has piles[i] bananas. The guards have gone and will come back in h hours.

Koko can decide her bananas-per-hour eating speed of k. Each hour, she chooses some pile and eats k bananas from it. If the pile has less than k bananas, she eats all of them and stops for the hour.

Return the minimum integer k such that she can eat all the bananas within h hours.

Input / Output Format

Input: Array piles, integer h. Output: Minimum eating speed k.

Examples

Example 1

Input: piles = [3,6,7,11], h = 8 → Output: 4

Example 2

Input: piles = [30,11,23,4,20], h = 5 → Output: 30

Example 3

Input: piles = [30,11,23,4,20], h = 6 → Output: 23

Approach Hints

• Binary search on k in range [1, max(piles)].
• For a given k, hours needed = sum(ceil(p / k) for p in piles). If hours <= h, k works → search lower; else search higher.
• Time: O(n log(max(piles))). Space: O(1).
• Use (p + k - 1) // k for ceiling division (avoid float).