FWIW: It's not too off topic because it's about an algorithm

The Guardian asked in a recent Monday puzzle for an optimal strategy to find the smallest and the biggest in a deck of 100 cards.

https://www.theguardian.com/science/2025/may/12/can-you-solve-it-are-you-craftier-than-a-cat-burglar

(It's not the rope riddle)

While my strategy was optimal like the proposed solution, they claimed the formal proof that there can't be any better solution to be "too technical" to be published there. (Pierre de Fermat giggles in his tomb).

The attempts in the comment section didn't impress me either.

Anyway I spent the last hours figuring out an elegant proof for a general formula of any numbers of cards.

But the comment section there is long closed and I thought the local crowd here would like to try their best too ...:)

So here the task again: (copied from above link)

<Reveal this spoiler or all in this thread>

Cheers Rolf
(addicted to the Perl Programming Language :)
see Wikisyntax for the Monastery

¹) It's quite rich to ask for an optimal strategy without presenting one...

In reply to 1. Go compare! Guardian's algortithm riddle and mathematical proof by LanX

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