CIS as a department does not have a set preferred citation style. However, different areas of study within CIS may have different expectations. For example, Library and Information Science journals are split between APA and Chicago depending on the subject of the publication. It's always best to ask your professor if they have a preferred style or how they would like you to attribute information in your code. Below is a link to the library's larger citation guide along with some quick tips for the three major citation styles and tips for citing code to get you started.
Coding is a very collaborative process, and the programming community is widely accepting of collaboration and reusing code to expand upon projects. However, it is important that you attribute code that you reference as you work through a problem, datasets that you use in your code, and any code that you might reuse from other programmers. The most transparent method of doing that in your own code is to use comments explaining your process and explicitly referencing attributions/citations when appropriate.
Publication Manual of the American Psychological Association by 