Hello Codeforces!
gyh20 and I are glad to invite you to Codeforces Round 670 (Div. 2) which will start on 12.09.2020 16:45 (Московское время). Note the unusual start time of the round.
The contest will last for two hours, and you will have five tasks to solve. The tasks are prepared by me and gyh20. This round is rated for participants whose rating is not higher than 2099. You can see that my current rating is exactly 2099 :)
There might be an interactive problem. You can learn about them here.
We would like to thank:
- isaf27 for coordinating and helping us with the problems.
- namanbansal013, Retired_cherry, morzer, Osama_Alkhodairy, TechNite, coderz189, physics0523, _zzw4257 for testing the problems and providing useful feedback. Special thanks to TechNite for helping us with writing the editorials, and physics0523 for improving one problem's solution!
- c2020HXW, Time_tears, fangzhijian2020 for discussing the problems with us.
- finally, MikeMirzayanov for great platforms Codeforces and Polygon!
We tried our best to make the statements short and clear, pretests strong and problems interesting. We hope you like the problems!
Score distribution will be announced shortly before the round.
Good luck and have fun!
Upd: Score distribution is 500-750-1250-1750-2500.
Upd: For problem reasons, the contest is delayed for 10 minutes. We are very sorry to keep you waiting, sorry again.
Upd: Score distribution is changed to 500-1000-1500-2000-2750.
Upd: The round is finished. We're really sorry for B being well-known (none of the testers knew the harder version of this problem in ABC173E). Still, congrarulations to the winners!
Div1 (unofficial):
Div2:
