use strict;
use Benchmark qw(timethese cmpthese);

my @array = (
    'four',
    'three',
    'three|four',
    'two',
    'two|four',
    'two|three',
    'two|three|four',
    'one',
    'one|four',
    'one|three',
    'one|three|four',
    'one|two',
    'one|two|four',
    'one|two|three',
    'one|two|three|four'
);

timethese(  10000,
            {'Schwartzian' => '&Schwartzian()',
             'Orcish'      => '&Orcish()',
             'Direct Sort' => '&DirectSort()',
            }
        );

cmpthese(  10000,
            {'Schwartzian' => '&Schwartzian()',
             'Orcish'      => '&Orcish()',
             'Direct Sort' => '&DirectSort()',
            }
        );

sub Schwartzian()
{
    my @sorted_array = map {$_->[1]}
                       sort {$b->[0] <=> $a->[0]}
                       map {[length($_), $_]} @array;
}

sub Orcish()
{
    my %m;
    my @sorted_array = sort {
        ($m{$b} ||= length($b)) <=> ($m{$a} ||= length($a))
    } @array;
}

sub DirectSort()
{
    my @sorted_array = sort {length $b <=> length $a} @array;
}