diffs

diffs.pl

#!/usr/bin/env perl

use strict;
use warnings;
use 5.018;

use Data::Dumper;
use Const::Fast;

const my $N => 1000;
const my $L => 50;

main();
##############################################################################

sub main {
    my $lists = init();
    my $diffs;

    open my $fh, '>', 'result.txt' or die 'cannot open';
    say $fh stringfy($_) foreach @{$lists};
    foreach my $i ( 0 .. scalar( @{$lists} ) - 1 ) {
        foreach my $j ( 0 .. scalar( @{$lists} ) - 1 ) {
            say $fh "$i => $j: "
              . sprintf( '%0.3f', compare( $lists->[$i], $lists->[$j] ) );
        }
    }
    close $fh;

}

sub init {
    my $lists = [];
    foreach my $i ( 0 .. $N - 1 ) {
        foreach my $j ( 0 .. $L - 1 ) {
            $lists->[$i][$j] = range_rand( 1, 9 );
        }
    }

    return $lists;
}

sub stringfy {
    join q{,}, map { sprintf '%03d', $_ } sort { $a <=> $b } @{ shift() };
}

sub compare {
    my @one = sort { $a <=> $b } @{ shift() };
    my @two = sort { $a <=> $b } @{ shift() };

    my ( %one, %two );
    $one{$_}++ foreach @one;
    foreach (@two) {
        if ( $one{$_} ) {
            $one{$_}--;
        }
        else {
            $two{$_}++;
        }
    }

    my $diffs = 0;
    $diffs += $_ foreach values %one;
    $diffs += $_ foreach values %two;

    return 1 - $diffs / ( @one + @two );
}

sub range_rand {
    my ( $a, $b ) = @_;

    return $a + int( rand( $b - $a + 1 ) );
}