[SPOILER] QOTW #23 Solution

Here's my solution. It's both short and easy to understand:

<<<
#!/usr/bin/perl -w

use strict;

my $N = shift;

sub recurse
{
    my ($string, $num_opened, $num_closed) = (@_);
    if (($num_opened == $N) && ($num_closed == $N))
    {
        print "$string\n";
        return;
    }
    elsif ($num_opened < $N)
    {
        recurse("$string(", $num_opened+1, $num_closed);
    }
    if ($num_opened > $num_closed)
    {
        recurse("$string)", $num_opened, $num_closed+1);
    }
}

recurse("", 0, 0);

>>>

Best regards,

	Shlomi Fish

-- 

---------------------------------------------------------------------
Shlomi Fish      shlomif-ik1l9ssToec+JF/[email protected]
Homepage:        http://shlomif.il.eu.org/

Knuth is not God! It took him two days to build the Roman Empire.