Thanks! I hope Richard was a better author than Dan - his stories are interesting but the writing ... not my cup of tea. I got stuck on the 1A/4D cross - never heard of either one. I have now learned a few things today!
As a genre, math textbooks are an acquired taste, but I can testify that at least IMO, the father's book is better written than the son's books. And sorry for the nerd Natick at 1A/4D!
Ah, the hours spent grinding through 4D’s book on algorithms in undergrad. Many a sleepless night on problems that in retrospect seem easy. As my former Russian colleagues were fond of saying, “All problems are either trivial or impossible.” (It sounds better in a thick Russian accent. Hit the ‘tr’ in trivial and the ‘o’ in impossible hard). The problem of course is identifying which problem fits into which category. I suppose crosswords are the same.