Type of Book: Digital or e-notes
Data Structures and Algorithms is one of the most important subject in Computer Science. Most of the books are in the eyes of the author Allen Downey who is known in the area are either too thoery oriented or too big or too bottom up.
Allen Downey tries rganizing the topics around an application—web search—that uses data structures extensively, and is an interesting and important topic in its own right.
This application also motivates some topics that are not usually covered in an introductory data structures class, including persistent data structures, with Redis, and streaming algorithms.
It is available free on Pustakkosh.com where as printed books can be bought from online.