IOM 2017, Блиц — Задача 18

OLYMPIAD OF METROPOLISES. Moscow, September 4 · 4 септември 2017 г.

Условие

You have a fifteen-story building and three identical hard drives. And you have a task of finding the highest floor one from which you can drop a hard drive without losing it’s functionality. If it breaks when dropped from the first floor, then the answer is 0. You can drop hard drives you have from whichever floor you want and then you can check if they are still working. What is the least number of drops required to find the wanted floor?

All hard drives break from the same height and this height does not change while the hard drive is still operational. This means that, if you drop a hard drive and it is still operational you can drop it from a different floor.

You can start dropping hard drives from the first floor, then the second, then the third and so on, until it breaks. This way you can find the answer in 15 drops. Of course, you can do it in fewer drops.

Отговори

Решение

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Оригинал в Архива: blitz.pdf · официални решения: answers-blitz.pdf