Back to Practice Dashboard
Top 150 InterviewEasy

Koko Eating Bananas

Learn how to solve the 'Koko Eating Bananas' problem. This detailed resource details brute force and optimized approaches.

Problem Statement

Easy

Koko loves to eat bananas. There are n piles of bananas, the ith 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 of bananas and eats k bananas from that pile. If the pile has less than k bananas, she eats all of them instead and will not eat any more bananas during this hour.

Koko likes to eat slowly but still wants to finish eating all the bananas before the guards return.

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

Write a function minEatingSpeed(piles: List[int], h: int) -> int.

Constraints
  • 1 <= len(piles) <= 10^4
  • len(piles) <= h <= 10^9
  • 1 <= piles[i] <= 10^9

Examples

Example 1
Input
piles = [3, 6, 7, 11], h = 8
Output
4
Explanation

At speed 4: pile 3 takes 1 hour, pile 6 takes 2 hours, pile 7 takes 2 hours, pile 11 takes 3 hours. Total = 8 hours.

Example 2
Input
piles = [30, 11, 23, 4, 20], h = 5
Output
30
Explanation

At speed 30: each pile takes 1 hour. Total = 5 hours.

Example 3
Input
piles = [30, 11, 23, 4, 20], h = 6
Output
23
Explanation

At speed 23: piles take 2+1+1+1+1 = 6 hours.

Need a Hint?
Analyze the input constraints. Try sorting first (O(n log n)) or using a hash map/set to track seen elements in O(n) time.
Edge Cases to Watch
  • Empty list or null input variables
  • Single item lists/arrays
  • Extremely large input bounds causing integer or stack overflow

Ready to Solve?

Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.

Open in Editor