Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good book, a very difficult read.

I purchased this book from Amazon last semester. While this book is a good product by itself, it makes for a very tough read. That didn't help since the subject itself is pretty tough for someone new to it. Topics that have been explained well to a decent degree Triangulation and Linear Programming. I found the explanations to Voronoi Diagram (pretty bad), Convex Hulls, Delaunay Triangulations, K-D trees, Range trees and Duality inadequate. Unfortunately, this is the best book that is both available and that I know of. The other book 'Computational Geometry' by Joseph O'Rourke was extensive as far as Convex Hulls and Triangulations were concerned, but bore significantly lesser matter - no LP, data structures and other important topics.