poor man's shuffle :)

in reply to Re: Curious find while comparing grep, map, and smart match...
in thread Curious find while comparing grep, map, and smart match...

Just for fun, here a poor mans shuffle:

  DB<228> sort { (-1)**(rand(2)%2)  } 1..10
 => (5, 8, 7, 6, 9, 10, 1, 4, 2, 3)
[download]

Surely neither efficient, nor well mixed and pretty pointless since List::Util is core. =)

Cheers Rolf

( addicted to the Perl Programming Language)

update

for completeness:

> nor well mixed

The distribution is perfect iff the list has 2^n elements

  DB<483> for (1..100000) {$x=0;$g[$x++]{$_}++ for sort {(-1) ** int r
+and 2} a..d }
 => ""

  DB<484> \@g
 => [
  { a => 25302, b => 25028, c => 24852, d => 24818 },
  { a => 25062, b => 24925, c => 24773, d => 25240 },
  { a => 24773, b => 24944, c => 25203, d => 25080 },
  { a => 24863, b => 25103, c => 25172, d => 24862 },
]
[download]

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Re: poor man's shuffle :) by BrowserUk (Patriarch) on Mar 27, 2013 at 19:52 UTC
Surely neither efficient, nor well mixed and pretty pointless ... Agreed.	[reply]
Re^2: poor man's shuffle :) by LanX (Saint) on Mar 27, 2013 at 19:55 UTC
> Agreed. =) Cheers Rolf ( addicted to the Perl Programming Language)	[reply]

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