Topswops is a card game created by John Conway in the 1970's. Assume you have a particular permutation of a set of n cards numbered 1..n on both of their faces, for example the arrangement of four cards given by [2, 4, 1, 3] where the leftmost card is on top. A round is composed of reversing the first m cards where m is the value of the topmost card. Rounds are repeated until the topmost card is the number 1 and the number of swaps is recorded. For our example the swaps produce:
[2, 4, 1, 3] # Initial shuffle
[4, 2, 1, 3]
[3, 1, 2, 4]
[2, 1, 3, 4]
[1, 2, 3, 4]
For a total of four swaps from the initial ordering to produce the terminating case where 1 is on top.
For a particular number n of cards, topswops(n) is the maximum swaps needed for any starting permutation of the n cards.
;Task:
The task is to generate and show here a table of n vs topswops(n) for n in the range 1..10 inclusive.
;Note:
[[oeis:A000375|Topswops]] is also known as [http://www.haskell.org/haskellwiki/Shootout/Fannkuch Fannkuch] from the German Pfannkuchen meaning [http://youtu.be/3biN6nQYqZY pancake].
;Related tasks:
* [[Number reversal game]]
* [[Sorting algorithms/Pancake sort]]