Hello, Codeforces!
Codeforces Round 1109 (Div. 3) will start at Jul/14/2026 17:35 (Moscow time). You will be offered 7 problems with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating of 1600 or higher, can register for the round unofficially.
The round will be hosted by rules of educational rounds (extended ICPC). Thus, solutions will be judged on preliminary tests during the round, and after the round, it will be a 12-hour phase of open hacks. After open hacks all accepted solutions will be rejudged on successful hacks.
You will be given 7 problems and 2 hours and 15 minutes to solve them.
Note that the penalty for the wrong submission in this round is 10 minutes.
Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:
- take part in at least five rated rounds (and solve at least one problem in each of them)
- do not have a point of 1900 or higher in the rating.
Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.
Problems have been created and written by itz_pabloo.
We would like to thank:
MikeMirzayanov for Polygon and Codeforces platforms.
Vladosiya for the excellent coordination.
Friendiks and Nickir for their help in preparing the problems.
Sokol080808, cry, AI-qv4rk, KotlechkovEgor, Fakewave for yellow testing.
SapeginIgor, dvb1r, VitaliiV, Gutark, feblokas, _liravel_, kaferius_cf for purple testing.
Maria_Chudinova, Yassia, Wileyne, Algolagon, veliak, eyfxrby, sanya37y, opa, Neckt00 for blue testing.
misha.arkhipov, s28b_shagabutdinov, Sava_is, nikk128, k_Teleport for cyan testing.
mlovbnee for grey testing.
Good luck!
