LeetCode 875 Koko Eating Bananas - Why Naive Fails

Try each possible speed from 1 to max(piles). For each speed, calculate the total hours needed.

There are up to $10^9$ possible speeds. Checking each takes $O(n)$. Total: $O(n \cdot \max(piles))$.

That's up to $10^{13}$ operations. Far too slow.