my $hash = {};
foreach my $line ( <DATA> )
{
    my ( $id, $type, $pos ) = split /\s+/, $line;
    $hash->{ $id } = { id   => $id,
                       type => $type,
                       pos  => $pos,
                     };
}

my $dup_hash = {};
foreach my $id ( keys %{ $hash } )
{
    my $type_pos = $hash->{ $id }{type} . '_' . $hash->{ $id }{pos};
    $dup_hash->{ $type_pos }{count}++;
    $dup_hash->{ $type_pos }{id} = $id;
}