Princeton University Computer Science Department

Computer Science 240 Reasoning about Computation Zeev Dvir

Fall 2025

Summary

An introduction to mathematical topics relevant to computer science. Combinatorics, probability and graph theory will be covered in the context of computer science applications. The course will present a computer science approach to thinking and modeling. Students will be introduced to fundamental concepts in theoretical computer science, such as NP-completeness and cryptography that arise from the world view of efficient computation.

Course Content

We will cover basic topics in math that are important in computer science as well as basic topics in theoretical computer science. The following is a rough estimation of the number of lectures spent on each topic: Mathematical Proofs (1.5 lectures); Combinatorics (2 lectures); Probability Theory (6 lectures); Midterm Exam (replacing 1 lecture); Graph Theory (4 lectures); Game Theory (1.5 lectures); Countable vs Uncountable Sets (1 lecture); Theoretical Computer Science (Computability, Complexity, Cryptography) (7 lectures).

Administrative Information

Lectures

MW 9:00AM-10:20AM.

The location of the Lectures can be found in the course registrar webpage.

Precepts

Please direct questions concerning your precept assignment to Colleen Kenny-McGinley, the CS Department's Undergraduate Program Manager. Colleen's contact information is provided later on this page. The course's professor, lead preceptors, and graduate student preceptors do not manage precept assignments.

The location of the Precepts can be found in the course registrar webpage.

Lead Instructor

Zeev Dvir, Ph.D. : email: zdvir (at) princeton.edu

Faculty Lead Preceptor

Iasonas Petras, Ph.D. : email: ipetras (at) cs.princeton.edu

Office Hours: M from 11:00AM to 3:00PM

Preceptors

Linrong Cai : email: lc1556 (at) princeton.edu

Office Hours: M from 5:00PM to 7:00PM, W from 12:30PM to 2:30PM

Michelle Le : email: nl8990 (at) princeton.edu

Office Hours: Tu from 11:00AM to 1:00PM, Tu from 7:00PM to 9:00PM

Aleksandr Storozhenko : email: as7649 (at) princeton.edu

Office Hours: Tu from 5:00PM to 7:00PM, F from 1:20PM to 3:20PM

Precepts start on Thursday 9/4

Preceptors' office hours start on Thursday 9/4. The office hours may change during the semester.

Undergraduate Graders

Lucy Wang

Ricky Chen

Ryan Chen

Siddhant Porwal

Lab Teaching Assistants

Alexander Khoretonenko

Dinesh Bhandari

John Matters

Nathan Kang

Ryo Mitsuhashi

Undergraduate Program Manager

Colleen Kenny-McGinley : CS Building 210, email: ckenny (at) cs.princeton.edu

Prerequisites

COS 126 and 226 (or sufficient mathematical background), and MAT 175 or MAT 202 or MAT 204. COS 226 can be taken along with COS 240 in the same term.

Textbooks and Other Reading

• Mathematics for Computer Science, Eric Lehman and Tom Leighton, 2004.

• Mathematics for Computer Science, Eric Lehman and F. Thomsom Leighton and Albert R. Meyer, 2010.

Academic Regulations

Please study the course Policies webpage.