CSCI 0220
Discrete Structures and Probability
CSCI 0220 meets Mondays, Wednesdays, and Fridays from 1:00 - 1:50 pm in Salomon DECI.
I don't know about you, but we're feeling 22! This class gives you the tools to explore interesting questions and convince yourself and others of their answers. You'll be introduced to new worlds of ideas and ways of thinking. We'll learn about Set Theory, Logic, Number Theory, Combinatorics, Graph Theory, and Probability. If these topics sound unfamiliar, not to fear: you're in exactly the right place! This course assumes no prior experience with these topics.

Assignments

Times listed are in EST. Assignments are released on Thursday mornings, and are due 11:59pm on Wednesdays.
Clicking on the "Overleaf Template" link will open a new Overleaf project, so you can write your homework solutions in LaTeX.
Homework | Template | Released | Due | Solutions |
---|---|---|---|---|
HW0 | - | Jan 25 | Jan 30 | - |
HW1 | Overleaf Template | Feb 2 | Feb 8 | HW1 Solutions |
HW2 | Overleaf Template | Feb 9 | Feb 15 | HW2 Solutions |
HW3 | Overleaf Template | Feb 16 | Feb 24 | HW3 Solutions |
HW4 | Overleaf Template | Feb 23 | Mar 1 | HW4 Solutions |
HW5 | Overleaf Template | Mar 3 | Mar 9 | HW5 Solutions |
HW6 | Overleaf Template | Mar 17 | Mar 22 | - |
HW7 | Overleaf Template | Apr 6 | Apr 12 | HW7 Solutions |
HW8 | Overleaf Template | Apr 13 | Apr 19 | HW8 Solutions |
HW9 | Overleaf Template | Apr 20 | Apr 26 | HW9 Solutions |
HW10 | Overleaf Template | April 27 | May 5th | HW10 Solutions |
Recitation sections are held from Thursday to Sunday, and recitation is due the week after your recitation section. LaTeX files for recitation packets can be found here. If you need to miss a recitation for a week, please use the Absence Form.
Recitation | Released | Solution |
---|---|---|
Recitation 1 | Feb 1 | Recitation 1 Solution |
Recitation 2 | Feb 8 | Recitation 2 Solution |
Recitation 3 | Feb 15 | Recitation 3 Solution |
Recitation 4 | Feb 22 | Recitation 4 Solution |
Recitation 5 | March 1 | Recitation 5 Solution |
Recitation 6 | March 8 | Recitation 6 Solution |
Midterm Review Guide | March 10 | - |
Practice Exam | Practice Exam Solutions | - |
Recitation 7 | April 5 | Recitation 7 Solution |
Recitation 8 | April 12 | Recitation 8 Solution |
Recitation 9 | April 19 | Recitation 9 Solution |
Recitation 10 | April 26 | Recitation 10 Solution |
Final Exam Review | - | Final Exam Review Solutions |
Final Practice Exam | - | Final Practice Exam Solutions |
Lectures

Lecture slides will be posted before each class. Topics are tentative and subject to change!
Lecture | Date | Topic | Recording |
---|---|---|---|
1 | January 25 | Video | |
2 | January 27 | Video | |
3 | January 30 | Video | |
4 | February 1 | Video | |
5 | February 3 | Video | |
6 | February 6 | Video | |
7 | February 8 | Video | |
8 | February 10 | Video | |
9 | February 13 | Video | |
10 | February 15 | Video | |
11 | February 17 | Video | |
- | February 20 | President's Day - NO CLASS | - |
12 | February 22 | Video | |
13 | February 24 | Video | |
14 | February 27 | Video | |
15 | March 1 | Video | |
16 | March 3 | Video | |
17 | March 6 | Video | |
18 | March 8 | Video | |
19 | March 10 | Video | |
20 | March 13 | Video | |
21 | March 15 | Video | |
- | March 17 | MIDTERM - IN CLASS | - |
22 | March 20 | Video | |
23 | March 22 | Video | |
- | March 24 |
Lean Practice - NO CLASS |
- |
- | March 27 | Spring Recess - NO CLASS | - |
- | March 29 | Spring Recess - NO CLASS | - |
- | March 31 | Spring Recess - NO CLASS | - |
24 | April 3 | Video | |
25 | April 5 | Video | |
26 | April 7 | Video | |
27 | April 10 | Video | |
28 | April 12 | Video | |
29 | April 14 | Video | |
30 | April 17 | Video | |
31 | April 19 | Video | |
32 | April 21 | Video | |
33 | April 24 | Video | |
34 | April 26 | Video |
Calendar

How do hours work?
CS22 hours are collaborative spaces for students to work together on problems, facilitated by TAs. Hours will be primarily in-person. More details about hours can be found in the Hours and Recitation Policy. Remote hours will be facilitated using tickets handled from Hours.
Here is a link to the course calendar (same as below).
Resources

Course Textbook
Mathematics for Computer Science — Lehman, Leighton, MeyerReading (and purchasing!) this textbook is not required, though many students in the past have found it helpful in reinforcing what's covered in lecture!
Course Documentation
Important Links
- EdStem
- Anonymous Feedback Form
- Extension Request Form
- Recitation Absence Form
- Lecture Recordings/Livestream
Homework Resources
For many of you, this is your first time writing proofs, and even for those who have written proofs before, what we consider a good proof in CS22 likely differs from what made a good proof wherever you were writing them before! Check out the proof virtues document below to acquaint yourself with what we consider a good proof in CS22. Your proofs will be graded with respect to this document , so be sure to read it carefully, and come to hours with any questions.
Math Resources
Sample Proofs
- Bidirectional
- Bijective Proof Sketch
- More Bijective Proof Sketches
- Bijective Strategies
- Cases
- Contradiction
- Contraposition
- Counterexample
- Equivalence Relations
- Induction
- More Induction
- Strong Induction
- Probability
- Set Equivalence
The LaTeX files to all the above resources can be found here.
LaTeX Resources
LaTeX (pronounced la-tek) is a program that you will be using to make your homework solutions look beautiful. The sample proofs above were written in LaTeX to give you an idea of what documents written in LaTeX look like. LaTeX allows you to incorporate mathematical notation into your proofs, and because this class involves a healthy dose of mathematical notation, LaTeX is going to be very useful! Using LaTeX is required after the 2nd homework.
We don't expect you've ever done this whole LaTeX business before, and that's why we're giving you some time to learn it! To get started, we recommend creating an account on Overleaf, an online program for writing and compiling LaTeX. After you do that, here are some links to check out: Honestly, please use Overleaf. It's so much easier than installing anything on your computer. Trust me.
- CS22 LaTeX Cheat Sheet (start here!)
- LaTeX GearUp Recording
- LaTeX GearUp Notes
- A Not So Short Introduction to LaTeX
- LaTeX Symbols Guide
- Art of Problem Solving: LaTeX
- LaTeX Intro Wikibook
- LaTeX on Brown CS Systems
In general, a really good resource for learning LaTeX is the web. When you have a question, google it, and you'll likely find someone who had the very same question!
Below is the course document class:
If you'd like to download LaTeX on your computer, here are some resources to do that:
If you're using LaTeX and you just don't know what the code for some symbol is, here is a helpful list to start:
Alternatively, this is a neat site which will return the LaTeX code based on handwritten input (although searching your question on the web is likely more efficient):
Staff

Instructor

Robert Y. Lewis
Instructor | Brookline, MA
He/Him
Call me Rob! I'm 50% computer scientist, 40% mathematician, and 10% philosopher, so this course is pretty much my dream.
Favorite Plant: Geranium
Head TAs

Josh Benzon
HTA | Fort Myers, Florida
He/Him
heya! i’m a junior studying cs. in my free time, i enjoy watching kdramas, listening to kpop, swimming, and vlogging 👀 #iykyk
Favorite Plant: Wolfsbane

Benjamin Goff
HTA | St. Louis, MO
He/Him
President of Brown Taekwondo 🦶
Favorite Plant: POTATO

Tyler Gurth
HTA | Parsippany, New Jersey
He/Him
Hey!! I'm a sophomore studying CS and History of Art and Architecture. When I'm not programming or appreciating art, one can find me throwing really heavy things.
Favorite Plant: Hydrangeas

Jania Vandevoorde
HTA | Dubai, United Arab Emirates
She/Her
Call me Janj! I'm a sophomore on the Rugby team studying CS and Statistics! I also love reading, traveling, and watching Survivor :)
Favorite Plant: The Whomping Willow from Harry Potter
STAs

Christian Armstrong
STA | Durango, Colorado
He/Him
Howdy! I'm a sophomore studying CS and I love to play basketball.
Favorite Plant: Aloe Vera

Carmen Yu
UTA-STA | Elk Grove, CA
She/Her
i enjoy math, philosophy, and warm weather :)
Favorite Plant: Aloe Vera
UTAs

Kristen Cai
UTA | Vernon Hills, IL
She/Her
Hi! I'm a sophomore studying APMA-CS. In my free time I enjoy playing piano & guitar, listening to music, and reading. Also I love mangoes :)
Favorite Plant: Orchid

Jen Chen
UTA | Livingston, NJ
She/Her
I like discrete math and probability
Favorite Plant: Monstera Adansonii

Stephen Chen
UTA | Plymouth, MN
He/Him
Hi! I'm a senior studying CS from Plymouth, Minnesota (right next to the Twin Cities). In my free time, you can find me either listening to the same three Taylor Swift songs on loop or losing in League of Legends.
Favorite Plant: Coconut Tree

Sam Devorsetz
UTA | New York, NY
He/Him
I'm a junior studying Math-CS. Also a big Red Hot Chili Peppers fan.
Favorite Plant: Seaweed

Ryan Edmonds
UTA | Plymouth, MA
He/Him
I am a Masters student with interests in mathematics and computer science. I enjoy video games and metal music!
Favorite Plant: Bonsai

Alan Gu
UTA | Millwood, NY
He/Him
I’m 22
Favorite Plant: Grass

En-Hua Holtz
UTA | Connecticut
Any/Any
I play organ and piano, and I compose and sing a cappella as well. I also write stories, and am a (now mostly inactive) Wikipedia editor. Fortunately for Wikipedia, the last two things are entirely separate.
Favorite Plant: Cape Sundew (Drosera capensis)

Kyle Lee
UTA | Santa Clara, CA
He/Him
I'm a junior concentrating in APMA-CS! #dubnation
Favorite Plant: Orchids

Alex Liang
UTA | Shanghai
He/Him
I enjoy playing basketball, binging Criminal Minds, and eating any microwave foods.
Favorite Plant: Venus Flytrap

Nick Liu
UTA | Washington, D.C.
He/Him
I enjoy running marathons!
Favorite Plant: Hibiscus

Sophie Ljung
UTA | Chicago
She/They
I’m passionate about the intersection of women’s health and technology. By the end of my time as a TA, I will be able to do a muscle-up - and you can witness my failed attempts at RockSpot :)
Favorite Plant: Cannabis Sativa 💚

Michelle Lu
UTA | Dallas, TX
She/Her
I enjoy singing, visiting cute cafes, and listening to the same song more times than I'd like to admit.
Favorite Plant: Chrysanthemum!

Vivian Lu
UTA | Seattle, WA
She/Her
Hi! I'm a junior studying apma-cs. I enjoy thrifting, painting, and watching New Girl.
Favorite Plant: Pothos

Liliana Mack
UTA | El Paso, Texas
She/They
My name is Liliana and I’m apart of the UFLi / First-Gen community. I’m from El Paso, Texas which is a border city with an arid climate which means I love desert flora! I’m currently a junior and I study a mix of CS, Math and Ethnic Studies. In my free time I enjoy running, skating or playing my guitar.
Favorite Plant: Ajo lily and desert willow

Allie Masthay
UTA | Simsbury, Connecticut
She/Her
Hi! I am a sophomore studying CS and I am super excited to TA 22! Outside of school I love baking, drinking Diet Coke, and exploring Providence with my friends.
Favorite Plant: Peonies

Anastasio Ortiz
UTA | Managua
He/Him
Hey! My name is Anastasio and I am a sophomore from Managua, Nicaragua. Some activities I like are board games, tennis and ice cream
Favorite Plant: Cactus

Vignesh Pandiarajan
UTA | San Ramon
He/Him
Spicy food connoisseur, loves cheese but cursed with lactose intolerance.
Favorite Plant: Living Stones!, Scientific Name: Lithops

Matthew Prenovitz
UTA | Erie, PA
He/Him
Hi guys, I'm a sophomore studying CS. I like cooking, playing tennis, video games, and movies. I'm excited to work with everyone this semester!
Favorite Plant: Tree

Joseph Rotella
UTA | Philadelphia, Pennsylvania
He/Him
I'm a junior studying math and CS. I can also be found playing piano, cycling, or reading in the Rock stacks.
Favorite Plant: Russian Sage

Cedric Sirianni
UTA | Clifton Park, New York
He/Him
Hey everybody! I'm a sophomore studying CS. Talk to me about anything music-related :)
Favorite Plant: Succulent

Shamel Sameer
UTA | Houston, Texas
He/Him
hey! I'm a sophomore studying cs + apma.
Favorite Plant: Spider Plant

Justin Shin
UTA | Bremen, GA
He/Him
Hi guys. I'm a sophomore studying APMA-CS. Pumped to be here!
Favorite Plant: Shrub

Nitin Sreekumar
UTA | Karumam, Kerala, India
He/Him
Hey I am a sophomore concentrating in Biology and CS. I love gardening, which is unfortunate because I am allergic to bees.
Favorite Plant: Cocos Nucifera

Eugene Still
UTA | Tulsa, Oklahoma
He/Him
Hi! I’m a sophomore studying APMA/CS. I like food, video games and anime. Excited to meet everyone.
Favorite Plant: Lettuce

Serena West
UTA | Houston, Texas
She/Her
Hi! I'm a sophomore concentrating in computational biology! I'm a fan of 0.5 pics and trying new foods! Excited to be here :)
Favorite Plant: Eucalyptus


April Xu
UTA | Frisco, TX
She/Her
passionate about walkable cities, transit-oriented development, and waffles ¨̮
Favorite Plant: Gardenia

Michael Youssef
UTA | Hopkinton, MA
He/Him
Hi! I'm a sophomore, and I have a caffeine addiction.
Favorite Plant: Venus Fly Trap

Ziwen Zhou
UTA | Philadelphia
He/Him
Hi everyone! I'm a senior studying APMA/CS. Feel free to challenge me to a game of chess! Excited to work with you all!
Favorite Plant: Snapdragon

Kai Zuang
UTA | Frisco, Tx
He/Him
hi im a sophomore concentrating in cs. when i'm not busy crying over psets i like to spend my free time catching sunsets, stargazing, or lying in the grass :)
Favorite Plant: Cannabis Indica 🍃