[nindalf]

Codegolf page with solutions up to 30 times faster than the McIlroy shell script solution - https://codegolf.stackexchange.com/questions/188133/bentleys...

[eru]

Interesting, that they can only get 30 times faster with modern technology and more complications.

I guess, if you really wanted to solve this fast, you'd massively parallelize.

In any case, this was more about easy of implementation than about runtime speed.