Koko Eating Bananas

mediumTests passed 2026-11-11v1.0.0

TC: O(N log M)|SC: O(1)

Binary Search Original Statement (leetcode).md

1. Core Invariant / The Trick

Monotonic predicate on speed `k` over `[1 .. max(piles)]`: calculate `sum(ceil(p / k))` (`(p + k - 1) // k` integer ceiling). Find the smallest `k` where total hours <= `h`.

2. Complexity Bounds & Proof

Binary search spans range `1..max(piles)` (size M); each check iterates N piles.

3. Minimal Idiomatic Code

def minEatingSpeed(piles: list[int], h: int) -> int:
    l, r = 1, max(piles)
    while l < r:
        m = (l + r) // 2
        hours = sum((p + m - 1) // m for p in piles)
        if hours <= h: r = m
        else: l = m + 1
    return l

4. Failure Modes & Interview Follow-ups

Pitfalls:- Integer division truncation vs ceiling division `(p + k - 1) // k`.

Follow-ups:- Capacity To Ship Packages Within D Days uses identical binary search on answer capacity.

Personal Notes & Scratchpad (Local-First Yjs CRDT)

Saved instantaneously in IndexedDB. Streams live across peers via Hocuspocus when signed in.

Related Invariants

Binary Search (O(log N))

Browser Scratchpad

Console Output

Click Run or press Cmd/Ctrl+Enter to execute locally in a Web Worker.