The book covers the same set of puzzlers which are on the website. However, in the book we provide much more detailed explanations and discussions. In addition, we use puzzlers to educate the reader on some relevant Scala features.
You can see for yourself the difference between the book and the online content, by reading the sample chapter:
http://www.artima.com/samples/ScalaPuzzlersCh2.pdf and comparing it with the online version:
http://scalapuzzlers.com/#pzzlr-003
