'Competitive Programming' in summary, is this: "Given well-known Computer Science problems, solve them as quickly as possible!". If you strive to be a competitive programmer - that is, if you want to do well to qualify and get a medal in IOI, or to qualify for ACM ICPC nationals, regionals, and up to the world finals, or in other programming contests - then this book is definitely for you!
In this book, you will learn basic to more intermediate/advanced data structures and algorithms frequently appearing in recent programming contests. However, you will not just learn the data structures and algorithms, but also how to implement them efficiently and apply them to appropriate contest problems.