Practicing Recursion in Java

Educators and students consider recursion one of the most difficult topics in introductory programming courses. The limited number of recursive examples in the textbooks is not sufficient for most students. This text is designed to help students in CS I or CS II courses to practice writing recursive code in Java. It may be helpful for instructors teaching those courses, as well. For them it can serve as a poll of test examples, or as a base to create projects that include variations of existing methods.

The book provides a collection of over 150 recursive examples on integers, arrays, linked lists, linked trees, and graphical examples. Each example includes a problem specified in English, solution at the algorithm level, and recursive code implemented in Java. Graphical examples have also a picture of the outcome that should be drawn in addition to code. Most of examples were given to my students on tests and final exams. The remaining problems are for advanced students who grasped the topic and want to be challenged to do more.