Select Code to Download

$t = {
    d => 'd',
...
        r => { d => 'g', l => 0, r => 0, },
    }
};

sub f{r(pop);$a{(pop)}||0;sub r{my$n=shift||return;$a{$n->{d}}=$n;r($n
+->{l});r($n->{r});};};