Re: Perl Quiz of the Week #23

colin.rafferty-/PgpppG8B+R7qynMiXIxWgC/[email protected] writes:

> Of course, what I'd really like is to have a (non-exponential)
> algorithm that calculates the number of lines in the answer.  So far,
> I have the following results.

Heh - I hadn't seen your message when I sent mine, but a quick and
dirty way to do the calculation if you've got my parencheck.pl script
from that message is:

perl -le 'print q[()] x 16' | perl parencheck.pl

And then read the error message.

Or you can rip out binom and catalan from that script and come up with
a nicer interface.

Given the exponential(*) nature of this particular problem, I wouldn't
worry about speed and focus instead on program elegance and simplicity
this time.

(*) The number of output lines is approximately 
    (4**n)/(sqrt(Pi) * n**1.5)
from: http://mathworld.wolfram.com/CatalanNumber.html