내가 돌아왔다! (Hello, Codeforces!)
I am thrilled to introduce you to Codeforces Round #633. Followings are basic information:
- This contest will take place on Apr/12/2020 17:05 (Moscow time).
- The round is rated for all participants who can understand this announcement. There will be two divisions.
- There are 5 problems in each division and you will have 2 hours to solve it.
- Score distribution will be announced later.
Followings are contributors:
- Authors: McDic (All Div.2 problems and Div.1 D), tzuyu_chou (Div.1 E)
- Coordinator: antontrygubO_o
- Phase 1 (When this round was supposed to be Div.2): dorijanlendvaj, SoulTch, pajenegod, AryaPawn, Rahul, mcdx9524, 300iq, Nemo, tfg
- Phase 2 (Before we knew that old Div1D can be easily googled): Um_nik, Ari, benson1029, khulegu, Sad_reacts_only, TselmegKh
- Phase 3 (Before few days to the round): mohammedehab2002, Kuroni, xuanquang1999, Maripium, MrDecomposition
- CF Admins: Thanks to MikeMirzayanov and his team for maintaining Codeforces and Polygon. I would like to say same sentence again as I said in my last round's announcement. Polygon is super great platform to prepare sports programming contest.
Followings are some fun things:
- antontrygubO_o is the most intense coordinator I have ever met. He rejected lots of my problems. Some example of rejection comments are below:
- This problem is too standard.
- Don't ask people about theorem and formula.
- This problem is appeared in recent ptz camp with higher constraints.
- I don't like it.
- Rock Scissor Paper makes statement messy, because some people don't know about it.
- D2A should be easier than this one.
- I've found generalized version of this problem in POI.
- Isn't this obvious?
- Your proof is wrong.
- This problem is not very interesting.
- This is too (censored).
- After lots of rejections, I tried my best to make problems to be interesting. I hope you like at least some of my problems.
- This round was originally supposed to be rated for Div.2 only. However, after we completed Phase 1 testing, we found that my round is too hard for Div.2, so we added more problems and made this round to be Div.1.
- In this round, statements will be even shorter than last contest.
- Even for some of problems which my coordinator approved, there were critical issues that made problems to be excluded. I will introduce some of my rejected problems which won't be used anymore in another post, after this contest ends.
I hope everyone can enjoy my third contest. Thanks in advance!
Followings are updates:
- Score Distribution:
- Div.1: 500 1000 1500 2000 2750
- Div.2: 500 750 1250 1750 2250
- I am sorry for such Div2C/Div1A statement issue. We fixed that immediately after few minutes to the round, but we should have announced it.
- Editorial is posted: https://codeforces.com/blog/entry/75913
- I opened new mashup for excluded problems. These problems are originally approved by antontrygubO_o but excluded for some reasons.
- Binomial Determinant is old Div1D. We found this problem on google so we removed this.
- Divisible Xor is old Div1A. But since we made 3 xor problems, we removed this one.
Followings are winners: