Comment by taeric

If it helps, you can find a treatment of this in Knuth's vol 4, I believe. Will have to see if I can actually solve it later.

Amusingly, this same basic problem was given to me by Google as an interview question. I was baffled, as I could name the problem, and knew of a reference book that covered it; but I wasn't able to just "on the fly" solve it. Felt like I was living a strawman of pointlessly difficult interview questions. (To be fully fair, I'm not sure I bombed this part. Been far too long for me to remember the other parts.)