# Koko Eating Bananas
Koko has `piles` of bananas and `h` hours before the guards return. Each hour she picks one pile and eats up to `speed` bananas from it (if the pile has fewer than `speed`, she finishes it and stops that hour). Return the minimum integer `speed` that lets her finish everything within `h` hours.
The exact 'binary search on the answer' pattern taught in Module 2 (recap 547 uses this same problem) — binary search over the *feasible speed*, not over the input array, using a monotonic feasibility check. Currently zero mock coverage of this pattern.
**Example:** `piles=[3,6,7,11], h=8` -> `4`.
Target complexity: O(N log(max(piles))).