Roller Coaster Chess

A while ago I drew a comic about playing chess on a roller coaster. Various xkcd readers took up the challenge. Pictured above: Andrew Burke, Chris Ranker, Ryan DowlingSoka, and Chance Brown. To see more pictures of chess on rides, go to xkcd.com/chesscoaster. If you think you can do better, go for it, and send […]

Perl Appetizers

You may have noticed that the knapsack problem in today’s comic has two solutions. I thought that (spoiler alert!) the 1, 0, 0, 2, 0, 1 solution was the only one, but 7, 0, 0, 0, 0, 0 — seven orders of mixed fruit — also works. Why did this happen? Well, I checked my […]