Every computer science curriculum in the world includes a course on data structures and algorithms. Data structures are that important; they improve our quality of life and even save lives on a regular basis. Many multi-million and several multi-billion dollar companies have been built around data structures.

How can this be? If we stop to think about it, we realize that we interact with data structures constantly.

• Open a file: File system data structures are used to locate the parts of that file on disk so they can be retrieved.
• Look up a contact on your phone: A data structure is used to look up a phone number in your contact list based on partial information even before you finish dialing/typing.
• Log in to your favorite social network: The network servers use your login information to look up your account information.

This list goes on and on.

This class provides a quick introduction to the concept of data structures for the beginner programmer. In most cases, it is suitable for high school students. This work contains code and/or text from opendatastructures.org.