The Art of Programming is the best book set for computer science ever written. It would be very difficult to overstate the value of the tree data structure in computing. In this book, Knuth gives the history of how the many uses of trees arose in the history of human problem solving. Concise with just enough detail, it is well worth reading. He frequently uses algorithms expressed in stepwise notation to make his points. However, the real value of this book is in the exercises at the end of the sections. An enormous amount of fundamental computer science is expressed in those 156 questions and detailed answers to all of the exercises are included in this book.