Codeforces is a Russian website dedicated to competitive programming. It was created and is maintained by a group of competitive programmers from Saratov State University led by Mikhail Mirzayanov. Since 2013, Codeforces has surpassed TopCoder in terms of active contestants . Codeforces Round #369 (Div. 2) contest broke all records in terms of registrants: 8670.
Codeforces provides the following main services to all users:
- participation in the short (2-hours) contests, so-called "Codeforces Rounds", held about once a week;
- participation in educational contests (2-2.5 hours), held 2-3 times per month
- challenge/hack other contestants solutions;
- ability to solve problems from previous contests for training purposes;
- "polygon" for creating and testing problems;
- kind of social-networking through the use of internal public blogs.
Contestants are rated by a system similar to ELO. There are usually no prizes for winners, though 2-3 times a year special contests are held, in which top performing contestants receive T-shirts. Some bigger contests (mostly local to a country) are hosted on Codeforces base, among them "Yandex Algorithm 2011", provided by Yandex, one of Russia's largest IT-companies.
The first Codeforces Round was held on the February 19, 2010 with 175 participants. As of the end of January 2016 over 300 rounds were held, with over 5000 registered competitors per round on average. Before 2012 Codeforces Rounds were titled "Codeforces Beta Rounds" to indicate that the system was still under development. However development of interconnected facilities such as training, virtual contests, new blog and interface features, etc. At the end of year 2015, Codeforces had over 300000 registered users .
Contests hosted by Codeforces
Some bigger contests are hosted on the Codeforces platform, among them: