Perl Golf

We have not figured out the rules, chosen the judges, or calculated what your chances of winning really are, but we do have the prizes – Perl Mongers hats or tshirts along with a chance for fame and glory in the next issue of The Perl Review.

Solve the following problem with a ridiculously low number of keystrokes, uses Perl in some clever or devious way, or is otherwise interesting and send it to comdog@panix.com.

Convert a base 36 number, with the digits [0-9A-Z], to its base 10 representation

If you would like to be a judge, or the maintainer of this column, or have an interesting golf problem, let us know. We can send you a hat or a t-shirt too.

#!/usr/bin/perl -wT
use strict;

my $base36 = shift;
$base36 = 10 if !defined $base36;
die "invalid input, only 0-9 and A-Z allowed\n"
    if $base36 !~ /^[0-9A-Z]+\z/;

my $dec = base36($base36);

print "$base36 => $dec\n";

sub base36 {
  #        1         2         3         4         5         6
  #234567890123456789012345678901234567890123456789012345678901
  $%+=$_*36**$?++for reverse map/\d/?$_:ord($_)-55,pop=~/./g;$%
}
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-Blake