http://qs321.pair.com?node_id=11128556


in reply to Re^2: Challenge: Ricochet Robots
in thread Challenge: Ricochet Robots

> Want a harder challenge?

Rather not. This was still manageable, but a harder one would be less fun. I have enough of them at work.

> did you have fun?

Yes, especially when I finished it! ;-)

> you need 2GB RAM

The original version that didn't produce the moves was less memory hungry. But the initial solution that stored the configuration as a string ate all my machine's memory and wasn't able to finish, so I had to introduce pack to make it more compact. I'd be interested in seeing an alternative solution.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]