Perfect shuffle: Difference between revisions

=={{header|SETL}}==

<syntaxhighlight lang="setl">program faro_shuffle;

loop for test in [8, 24, 52, 100, 1020, 1024, 10000] do

print(lpad(str test, 5) + " cards: " + lpad(str cycle [1..test], 4));

end loop;

op cycle(l);

start := l;

loop until l = start do

l := shuffle l;

n +:= 1;

end loop;

return n;

end op;

op shuffle(l);

return [l(mapindex(i,#l)) : i in [1..#l]];

end op;

proc mapindex(i, size);

return if odd i then i div 2+1 else (i+size) div 2 end;

end proc;

end program;</syntaxhighlight>

{{out}}

<pre> 8 cards: 3

24 cards: 11

52 cards: 8

100 cards: 30

1020 cards: 1018

1024 cards: 10

10000 cards: 300</pre>