By pikmike, history, 42 hours ago, translation,

Hello Codeforces!

Series of Educational Rounds continue being held as Harbour.Space University initiative! You can read the details about the cooperation between Harbour.Space University and Codeforces in the blog post.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Roman Roms Glazov, Adilbek adedalic Dalabaev, Vladimir vovuh Petrov, Ivan BledDest Androsov, Maksim Ne0n25 Mescheryakov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

• +126

By codingkshatriya, history, 15 hours ago,

In the wake of current contests, observation has become very crucial in every problem, thinking from the problem statement and trying to reach the solution is no longer easy, because the crucial observation is no longer easy to arrive from the problem statement alone, I think we have to start from random points and see if we can reach solution from there.

Let's take today's C (Edu round 99), the crucial observation here is Bob can't win more than y matches, and there is a way for him to always win y matches, this was not easy for me, I saw the high number of AC's lowered my thinking scope, saw the sample, observed the pattern then tried to justify it. If there had been no sample, and I had not seen the submissions, I probably would have taken more time.

And unpredictability factor has increased, sometimes you get the observation in a few seconds, and at times you never get it, this definitely has impacted the ratings.

Any suggestions or comments on this are welcome.

EDIT : Some have misinterpreted my post, I am not complaining nor am I urging the problem setters to change the format, my post is more about how to tackle these kinds of problems, before screaming practice, add me as your friend have a look at the number of problems I have solved in the standings. And regarding unpredictability, I think it makes sense, even experienced coders at times have a blind spot, and relatively young ones may get that observation immediately, that's why I said it's more about the thinking style.

• +138

By proggerkz, history, 39 hours ago, translation,

Hi everyone!

To: I’m fine)

• +8

By KAN, 42 hours ago, translation,

• +168

By dapingguo8, history, 18 hours ago,

What else can I say? Congratulations for having $10^8$ submissions, codeforces.

• +219

# SecondThread vs. galen_colin Lockout Duel (ft. neal, stevenkplus)

Good morning everyone!

There are three great unsolved questions on Codeforces that every pupil dreams to one day know the answer to:

• What's the best opening move when playing the Epsilon Guessing Game against a geometry problem?
• How many cyans is Um_nik worth, modulo $10^9+7$?
• Who is really the 229th best programmer on Codeforces: SecondThread or galen_colin?

While we may never know the answer to the first two, Colin and I will settle the third question once and for all this Sunday in a 1v1 duel! Don't miss it!

Join us at this time on Sunday where we will compete head-to-head in a 1v1 lockout at https://www.twitch.tv/nealwu, with live commentary from neal!

Update: stevenkplus, the initiator of the first Lockout grudge match, will be co-commentating as well! Woohoo!

Update: YouTube video of the duel is posted: https://www.youtube.com/watch?v=WCqs6hbTMJY. Now includes Twitch chat!

Exciting clip of the last minute of the duel -- spoiler alert: https://www.twitch.tv/nealwu/clip/ConfidentGenerousTarsierDoubleRainbow

• +450

By MidoriFuse, history, 18 hours ago,

Unfortunately it's ongoing contest so can't actually view it. But congratulations on the Accepted!!!

• +200

By Ant_Man, history, 43 hours ago,

How to solve B, E, F, G, H, I, J?

• +54

By Monogon, history, 3 days ago,

The upcoming round has an unusual starting time. In order to keep my performance slightly less bad than usual, I will apply the "destroy my sleep schedule" strategy. For some unknown reason I have decided to document this by beginning my streaming career.

https://www.twitch.tv/monogoncoding

• +248

By qerty1234567, history, 14 hours ago,

Question A code( which got hacked) Qusetion B code(which got hacked) Above two are the hacked code which got hacked by a coder and below are his submission:- Question A code of coder who hacked Question B code of coder who hacked The only difference between two is only an addition of an extra case with wrong output in an if condition in both the questions.He did that and then hacked it from the original id of this fake coder.