Koko Eating Bananas - Binary Search on Answer

Instead of searching an array, you search over possible eating speeds. The key insight: if speed $k$ works, any speed $> k$ also works. This monotonicity enables binary search.

$1.$ Search range: $[1, \max(piles)]$.

$2.$ For each candidate speed mid, compute total hours needed: $\sum \lceil piles[i] / mid \rceil$.

$3.$ If hours $\leq h$, the speed works. Try smaller speeds (set right = mid).

$4.$ If hours $> h$, speed is too slow. Set left = mid + 1.

$5.$ Return left as the minimum valid speed.