# We'll pass it as ref to SCALAR and receive it in a ref to ARRAY
use constant ARTICLES => 100;
use constant ENTRIES  => 2000;

#Articles
foreach $article ( 1 .. ARTICLES ) {
    foreach $feature ( 1 .. 10 ) {
        $A->{$article}{$feature} = int rand(100);
    }
}

#Entries
foreach $entry ( 1 .. ENTRIES ) {
    foreach $feature ( 1 .. 10 ) {
        $E->{$entry}{$feature} = int rand(100);
    }
}
$| += 1;
foreach my $article ( 1 .. ARTICLES ) {
    foreach $entry ( 1 .. ENTRIES ) {

        #	print "." if $entry % 1000 == 0;
        my $count;
        foreach $feature ( 1 .. 10 ) {
            if ( $E->{$entry}{$feature} eq $A->{$article}{$feature}){
                $count += 1;
            }

        }
        if ( $count >= 3 ) {
            #Found match
            push @{ $X->{$article} }, $entry;

          
        }
    }
}
foreach my $article ( sort { $a <=> $b } keys %{$X} ) {
    print "$article:";
    foreach my $entry ( @{ $X->{$article} } ) {
        print "\t$entry";
    }
    print "\n";
}