As the title suggests, there will be a lockout tournament targeted towards pre-college students, organized by (in no particular order) lethan3, ezraft, PurpleCrayon, GusterGoose27, Apple_Method, codetiger927, qpwoeirut, clcos, jamster, and izhang.

Timing

The opening ceremony will start April 29 around 10:30 AM Pacific time (click the link to see the converted time), where tournament specific rules and the structure will be announced.

It will last for an expected 4 hours. You can check the website for more details.

All problems for the lockout matches will come from the Codeforces problemset, so the starting time may be modified depending on how fast system tests for round 869 go.

Who can participate?

The main tournament is intended for precollege participants.

Non-precollege participants can join to spectate or play some casual matches.

How to participate?

Join the Discord server. Also see the website for more information.

Format

Double-elimination.

Again, for more details, please visit the website or join the Discord server. Most logistics will be handled through the latter.

Also, SecondThread will be streaming and commentating the tournament! The link will be added here tomorrow.

Update

We would like to congratulate the winners of the Lockout Tournament Official (Pre-College) Division:

1. Dominater069

2. amoeba1

3. skittles1412

4. oursaco

5. Adam_GS

6. hazzler

7. Dewi

8. One

And we would like to congratulate the winner and the only present participant :flushed: of the Unofficial Division:

1. ScarletS

Check out the recording of the livestream here!

Thank you, participants, for such a successful tournament! We hope you enjoyed dueling with us and had fun!

Some stats about the round

Solutions

Problem A

Problem B

Problem C

Problem D1

Problem D2

Problem E

Hi Codeforces,

We're excited to invite you to Codeforces Round 809 (Div. 2), which will take place at Jul/18/2022 17:35 (Moscow time). All problems were created and prepared by lunchbox, lce4113, and me. It will be rated for all participants with ratings lower than 2100.

Thanks to the people that made this round possible:

• IgorI for coordinating the round, patiently guiding us through the preparation process, and translating all statements to Russian.
• KAN, for guiding and assisting IgorI in the coordination.
• Apple_Method, izhang, lethan3, moo., null_awe, and ezraft for proposing problems that didn't make it to the final version of the round.
• PurpleCrayon for feedback and suggestions in the early stages of the round.
• Our testers, for their time and feedback: EnDeRBeaT, Queue, AlperenT, FairyWinx, ak2006, TheScrasse, sus, SirPh, litesam, asrinivasan007, Igorbunov, Runtime-Terr0r, timreizin, and Aaeria.
• MikeMirzayanov for the excellent platforms Codeforces and Polygon.

You will be given 2 hours to solve 5 problems, one of which will be divided into 2 subtasks. The scoring distribution will be announced later.

UPD: The scoring distribution will be $$$500 - 1000 - 1250 - (1000 + 1250) - 2250$$$.

UPD2: The editorial has been posted at https://codeforces.com/blog/entry/105008.

UPD3: Winners

Official

1. WYZFL
2. c8k
3. tiger1926
4. b6e0
5. iztrax

Everyone

1. tourist
2. SSRS_
3. WYZFL
4. Rubikun
5. noimi