[vram22]

P.S.: What I call the Bentley-Knuth problem (for lack of a better term) is also interesting. Bentley posed it to Knuth. I read about it in a blog post and wrote solutions for it (unoptimized) in both Python and shell:

http://jugad2.blogspot.in/2012/07/the-bentley-knuth-problem-...

The original blog post that I read is here:

More shell, less egg: http://www.leancrew.com/all-this/2011/12/more-shell-less-egg...

It has many comments which are interesting.