FAQ

On Friday 09 September 2005 10:15, Terje Kristensen wrote:
Yep, your eyes does not deceive you. We have actually started a new golf
here at http://terje2.perlgolf.org

I hope there still is some perl golfers out there itching for a new
challenge.

The task this time is called "beads".

Terje and Mtve
Thanks for the new golf!

In any case, there's an exploitable "feature" in the count sub-routine in the
testsuite:

<<<
sub count {
my ($hole, $tie) = @_;
local $_ = slurp($props{$hole}{work}, $binary);
if (/^\#!/) {
s/^\#![\t ]?\S+// && s/\n//;
}
s/\s*\z//; <--------
my $md5 = md5_hex($_);
my $score = length;
my $normal = $score ? y/ -~\t\n// / $score : 1;
if (defined($tie)) {
defined(my $code = $tie_map{lc($tie)}) ||
die "Unknown tie function $tie\n";
$score += $code->($_, $score)/$nr_ties if $score;
$ties++;
}
return ($score, $md5, $normal*100);
}

>>>

What happens is that trailing whitespace is removed. But one can use it to
encode the entire program, no matter how long it is, and get a 25 characters
solution. Like this:

<<<
#!/usr/bin/perl

use strict;
use warnings;

use IO::All;

my @code = io("beads.pl")->getlines();

my $bleach = join("", unpack("b*", ";$code[1]"));
$bleach =~ s!0! !g;
$bleach =~ s!1!\t!g;

io("bleach/beads.pl")->print(
qq{open 0;eval pack"ab*",<0>\n$bleach}
);
>>>

This is not my original idea: Piotr Fusik used it for his solution in the last
kernelpanic.pl Perl golf.

But I suggest issuing a new beadstest.pl file so that people won't all submit
25-characters solutions and this would be more of a real golf. It should be
noted in the subsequent golfs as well.

Regards,

Shlomi Fish (who would now be working hard on optimizing his relatively long
solution)

---------------------------------------------------------------------
Shlomi Fish shlomif@iglu.org.il
Homepage: http://www.shlomifish.org/

95% of the programmers consider 95% of the code they did not write, in the
bottom 5%.

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groupgolf @
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postedSep 9, '05 at 7:15a
activeSep 23, '05 at 6:41p
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