my ( $m, $k ) = optimise(30000000, 0.0001);

print <<"";
memory usage = $m
hash functions = $k

sub optimise {
    my ( $num_keys, $error_rate ) = @_;
    my $lowest_m;
    my $best_k = 1;
    
    foreach my $k ( 1..100 ) {
        my $m = (-1 * $k * $num_keys) / 
            ( log( 1 - ($error_rate ** (1/$k))));
    
        if ( !defined $lowest_m or ($m < $lowest_m) ) {
            $lowest_m = $m;
            $best_k   = $k;
        }
    }
    return ( $lowest_m, $best_k );
}