CS173: Discrete Structures, Fall 2021

Welcome CS 173, Fall 2021!

This term, all lectures of CS 173 are sharing one web site because we will be running in sync.

Please look through the links above to get familiar with the syllabus and the tools that we'll be using. This page provides a quick summary to deal with immediate issues. See also information about registration and prerequisites, the honors add-on, and special situations.


Add yourself to our piazza site now. The link is in the menu above. Piazza is our forum for announcements, asking questions, and so forth. It is particularly important to stay connected with piazza because some sections don't have physical meetings this term.


The lecture content will be pre-recorded and available on the lectures page (see menu above). The synchronous lecture periods will be used for weekly examlets and tutorial (small group) activities. Specifically

The instructor office hours the first two weeks are primarily for resolving practical problems, such as questions about course logistics, registration problems and disability accommodations.

Class zoom links

ALL sections will be on zoom on Wednesdays. The A and B times include both in-person and over-Zoom sections; please attend whichever time and whichever modality you are registered for, so that we can ensure that each has an appropriate number of staff.​ Zoom links for the various lecture times are here:

Make sure that you are logged into Zoom with your U. Illinois (netID) credentials.

Workflow for one topic

Here is the normal workflow for one topic (after the first couple weeks):

  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
Week K Do the readings; watch the lecture videos Tutorial   Homework due (late evening)
Week K+1   Examlet  

Here's the summary calendar for the whole semester; look at the Lectures tab (above) to see how the sequence of topics fits together in more detail.

  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
Week 1

Do the readings;

Watch the lecture videos

Tutorial 1   Office hours     Homework due (late evening)
Week 2 Tutorial 2   Office hours    
Week 3 Labor Day   Examlet 1    
Week 4 Tutorial 3   Examlet 2    
Week 5 Tutorial 4   Examlet 3    
... ...
Week 14 Tutorial 13   Examlet 12    
Week 15 Tutorial 14   No examlet (makeups only)    
Final week "Final" (size and weight of 2 examlets)

Homeworks and Tutorials

Study problems and the problems for the tutorials can be found on the Tutorials page.

You are expected to come to the tutorial class each week and make a good-faith attempt to work on the problems in your assigned group.

Each Saturday evening, there will be two pieces of homework due on PrairieLearn.