Internet Problem Solving Contest

Welcome to IPSC

The Internet Problem Solving Contest is an online programming competition for teams of up to three people. Each year, hundreds of teams gather to solve challenging problems and test their skills against some of the best programmers in the world.

The problems range from easy to very hard, so everyone is welcome to compete. We also have separate ranklists for individuals and secondary school students. You can use any programming language, or even solve problems by hand. Most of the problems are algorithmic in nature, but IPSC is particularly known for its unusual and fun problems. Here are some of our favorites:

If that sounds interesting, you should compete in the next IPSC! Until then, you can also try solving the above problems in the Training Area. Or browse through our Archive and see if anything else catches your eye.

How to compete

  1. Find a team of up to 3 people, or compete as an individual.
  2. Read the contest rules and register for the contest.
  3. Optionally, take part in the practice session to see how the contest works – especially if you're competing for the first time.
  4. When the contest starts, read the problem statements and begin solving.
  5. Choose a problem, download its input files, and try to write a program that produces the correct output file.
  6. Submit the output file and wait until it's judged "OK" or "Wrong answer".
  7. Repeat that until you have solved everything.

IPSC 2016 is over

IPSC 2016 took place from 18 June 2016, 11:00 UTC to 18 June 2016, 16:00 UTC.

Congratulations to the winners, and thanks to everyone who participated! We hope you had fun, and we're looking forward to seeing you again next year.

Open DivisionSecondary School Division
shik, step5, peter50216 from Taiwan, representing National Taiwan University
Team MooOOoOooOOOOoOooooSeP
Alexander Wei, Timothy Li, Kevin Sun from (multiple countries), representing Phillips Exeter Academy, Don Mills Collegiate Institute, Phillips Exeter Academy
Open Division (individuals)Secondary School Division (individuals)
Team Omega Double Jump
Rattly from Japan
Team 박수찬
박수찬 (17) from South Korea, representing 동래고등학교

If you missed the contest, don't worry! IPSC 2016 is available as a virtual contest in the Training Area.

Postcard Quest

We still don't have enough postcards from all over the world. Therefore the annual special task remains: You are encouraged to send us a nice postcard. If the postcard arrives before IPSC 2016 begins, your team will be awarded -60 penalty minutes. (Don't forget to write the name of your team on the back of the postcard.)

Our address: KSP, KZVI FMFI UK, Mlynska dolina, 842 48 Bratislava, Slovakia.