Competition Programming and Problem Solving

15-195 and 15-295 Spring 2025

In this course you will learn the techniques and skills needed to solve algorithmic programming contests problems such as those that appear on the International Collegiagte Programming Contest (ICPC), Codeforces, DMOJ, and AtCoder. Much of your time will be spent writing programs on your own to solve problems. (If you are interested in participating in the ICPC see this page.)

But the skills you will pick up from the course are far more valuable than just enabling you to win contests. Many of the algorithms and techniques are classic ones that every computer scientist should know. You will also learn to think about algorithms in a deeper way, because many of the problems require you have to devise a new algorithm, not just apply a classic one. You will also become highly fluent in a programming language of your choice. These skills will be of great value in your other classes, in your job interviews, and in your future work, not to mention the satisfaction you will get from solving these problems.

Basic Information
Weekly Problems
Rules and Academic Integrity
Grading
Logistics
Training Resources
Learning Material
Diversity, Equity and Inclusion

Basic Information

The regular weekly classes will take place Wednesdays beginning at 6:30pm in Scaife Hall 236, and last 2.5 hours (you don't have to stay the whole time.) There will usually be a lecture at the beginning of class for about 1/2 hour. This is followed by a contest in which you will solve as many problems as you can in the next two hours.

The theme of the contest, if it has one, will be announced on this website and on Discord, along with links to tutorials or background materials. When there are lectures, they will cover introductory content aimed at beginners to competitive programming. During the contests, the instructors will be available for help in the classroom, or via Discord. One point is give per problem solved, and 1/2 point is given for the problems can be solved throughout the next week. (See the section on grading below.)

After the contest, a solution document will be posted for the problems of the week. It will contain descriptions of algorithms to solve the problems. It will be jointly prepared by students in the class (i.e. you) and the instructors.

For more information on how to join these groups, etc, see the Logistics section below.

Weekly Contests

Week #1 (January 15): Introduction

This week has no particular algorithmic theme. Instead, we will go over the basics of competitive programming and do our first contest on Codeforces.com. Please make sure you have a Codeforces account ready to go and understand how to upload your solutions to the problems.

If you don't know how to read from standard input and write to standard output, here's a tutorial showing how to do it.

Contest Link: Here
Solutions: For editing For viewing

Rules and Academic Integrity

You can make use of generic on-line resources while solving problems. These include things like language documentation, API documentation, algorithm descriptions, terminology, etc. You are allowed to use any code you have written, at any time in the past, for any purpose. However, you should not search for or make use of code written by others to solve the specific assigned problem.

So to summarize, each student should write his or her own code. If you're stuck on a problem, you are welcome to discuss it with another student in the class, or the course staff. But you cannot copy another student's code.

The violations described above are regarded as an academic integrity violation, and -- depending on the severity -- will result in penalties and/or be reported to the appropriate university authorities.

Grading

This course is 5 units. Each week you will be given several problems to try to solve during class. You will be allowed (for half credit) to solve these problems during the week after the contest ends. You can also get credit for solving problems during rated contests on Codeforces. (This site run rated contests approximately every two weeks.)

To be more specific, you can earn points from the following sources:

The differences between 15-195 and 15-295 are: Students enrolled in 15-295 will not get credit for problems A and B of the weekly contests, but 15-195 students can. A student can take 15-195 only once, but 15-295 can be taken repeatedly.

Here is how your grade is determined:

score ≥ 25: A
score ≥ 15: B
score ≥ 10: C
score ≥   5: D

Logistics

Training Resources

There are many online resources available for you to train with if you intend to become a serious competitive programmer. You can find thousands of practice problems for you practice and improve your skills. Some good places to find practice problems include:

Learning Material

If you are a beginner looking for resources to learn the various topics that appear in typical contests, some good sources are:

Diversity, Equity, and Inclusion

We must treat every individual with respect. We are diverse in many ways, and this diversity is fundamental to building and maintaining an equitable and inclusive campus community. Diversity can refer to multiple ways that we identify ourselves, including but not limited to race, color, national origin, language, sex, disability, age, sexual orientation, gender identity, religion, creed, ancestry, belief, veteran status, or genetic information. Each of these diverse identities, along with many others not mentioned here, shape the perspectives our students, faculty, and staff bring to our campus. We, at CMU, will work to promote diversity, equity and inclusion not only because diversity fuels excellence and innovation, but because we want to pursue justice. We acknowledge our imperfections while we also fully commit to the work, inside and outside of our classrooms, of building and sustaining a campus community that increasingly embraces these core values.

Each of us is responsible for creating a safer, more inclusive environment.

Unfortunately, incidents of bias or discrimination do occur, whether intentional or unintentional. They contribute to creating an unwelcoming environment for individuals and groups at the university. Therefore, the university encourages anyone who experiences or observes unfair or hostile treatment on the basis of identity to speak out for justice and support, within the moment of the incident or after the incident has passed. Anyone can share these experiences using the following resources:

All reports will be documented and deliberated to determine if there should be any following actions. Regardless of incident type, the university will use all shared experiences to transform our campus climate to be more equitable and just.


Danny Sleator
Last modified: Wed Jan 15 22:16:21 2025