И снова привет, Codeforces!
Мы с Artyom123 рады пригласить вас на Codeforces Round 708 (Div. 2), который состоится в Mar/17/2021 17:35 (Moscow time). Раунд будет рейтинговым для всех участников, чей рейтинг ниже 2100.
Вот очень крутые люди, которых мы хотим поблагодарить:
- isaf27 за координацию раунда и идеи по его улучшению
- physics0523, Kotehok3, Ziware, Kirill22, Absyarka, AliShahali1382, notTehlka, Mohammad_Yasser, FairyWinx, kassutta, LazyPrime, kalki411 за тестирование раунда и фидбек
- MikeMirzayanov за всеми любимые платформы Codeforces и Polygon.
У вас будет 2 часа на решение 5 задач (и 2 подзадач). В этот раз условия не связаны с вселенной Valorant, хотя мы до сих пор иногда в него заходим.
Мы надеемся, что вам понравятся все задачи и вы не столкнётесь ни с какими проблемами во время контеста. Удачи!
Разбалловка задач: 500 — 750 — (750 + 500) — 1750 — (1500 + 1500)
UPD: Разбор
Has anyone heard about Hsoowedar Algorithm?
It's Radewoosh written backwards
If only I had such ability to recognize patterns....
you love dp that implies you love patterns too.
loving doesn't imply being excellent at it.
So early Score Distribution
good luck to everyone!
I don't know what is subtask, can you please explain it a bit?
Does it mean there's a C1, C2, E1, E2?
Yes
I think as usual C2 will be harder than C1 and E2 will be harder then E1.
Question: why score for C1 is higher than score for C2 and score for E1 is equal to score for E2 ?
C1-750
(C1+C2) — 750+500
Are you sure?
Ones who will solve C2 will obviously solve C1 as well.
You are right, but I want to say: are you sure that score for C2 will be 750 + 500?
I've edited my reply.
Now its OK!
That's not always true. Sometimes the two are completely different problems, like asking for min solution and max solution
ug its based on difficulty/complexity of solution ..maybe C2 is a trivial subtask
Its important word: maybe.
As a good tester, I was invited as a tester and I can test the round again! I hope you're enjoying the round!
Hoping for short statements just like round announcement ^_^
As a Tester it was grater experience to solve problems!
Good luck everyone! Hope I can become master at once.
Good luck!
As a tester, I want something and you all know what I want. So please.....
The problems are nice and the statements are clear
As a tester, you should complain if the statements are not clear beforehand to ensure that they are (;
What about test cases?
Testers can't know much about test cases; the most they can do is submit wrong solutions and see if they get WA/TLE or not.
I'm curious how shishyando proposed this round because as far as I know, you should be Orange (2100+) to propose the round.
Click
This is the fastest score distribution I've ever seen. I think this will be a hard round for me...
I've just get a -33 $$$\Delta$$$ rating in the last contest. Hope I'll break this streak soon in this contest or I'll return to a pupil. :/ Wish me luck :)
Actually not that difficult...
I've solved A,B,C(both C1 and C2) in this contest... The best performance I've ever had since my first contest...
But it's sad that it has gotten unrated :(
.
...
Привет shishyando, your last contest had a nice problemset, specially loved Sage's Birthday.
But a lot of subissions had FST on Problem A. Let's hope for strong pretests and a smoother experience this time.
Сейчас бы участвовать в контестах от ивановцев
All the best everyone!!!
I hope everyone gets high delta and learns some new things from problems.
Pretests(even system tests) are not strong enough in your last round,plz make stronger tests for this round
Just love the short and crisp announcement of this round.
Hope to have them implemented in problem statements as well. :-)
Unfortunately solved till c1 and got to know that contest is declared unrated.
A fair decision. :)
what an epic score distribution, looking forward to the contest
i want to see constructive problems!
okay i don't want to see that So stop downvotes please~~
Now you are eligible to get downvote from those 2
People who love contstructive
People who don't love contstructive
Now you are eligible to get +delta contribution for such 2 argument
good note
You are div1 participant
be creative
be yourself
looks like people who love constructives are winning
4 contests within 6 days...... <3.... week of Contests.......
4 contests within 6 days.....<3...... Week Of contests.......
As a participant I want to see problems with short and clear statements and without any legends stories and histories.
And I am sure that many participants want to see this like me.
Good luck to everyone!
I am ready to solve one problem ,just one !
good luck everyone!
.
.
An online game, just like counter strike.
His next question: What is counter strike?
An online game, just like valorant :)
What is an online game?
Valorant. -> What is valorant? -> Counter strike. -> What is counter strike? -> Valorant. -> What is valorant? -> ......
It looks like an endless cycle :-)
You can just simply google it.
Are the statements about metro game? "Artyom" is the main protagonist from that game.
Its always nice to get downvoted
Why??
Evidently it will be speedforces. May the fastest win.
Ok, may the fastest win
Hi my name is Oleg Dudka!!! Where can i find Alexandr Malkov from Sovetsk (Kirovskaya Oblast)>
проверить панель поиска codeforces?
very well
I can bet this is gooing to be speedforces with very less difficulty gap among initial few questin and then a big gap between any two
Round will be balanced!!!!
"вы не столкнётесь ни с какими проблемами во время контеста."
а что мне решать тогда?!
Russia is an actually a good country :D
2 Subtasks. Uh-oh. Stinky...
Is it still rated ?
As We m1.codeforces , m2.codeforces , m3.codeforces were working fine I think and I hope not
Well m3 couldnt load problems for me but if they didnt announced during the contest that it will be unrated, then it will probably be rated i guess ?
They have also put a reminder to use the alternate sites long ago.And alternate sites are made for such situations only. So it should be rated I think.
.
"Currently, we don't see reasons to make the round unrated.". Get yourself a pair of glasses or something I don't know, we can't really help with that.
Maybe the argument that we should've used m1/m2/m3 would hold some water if the links to those websites were always available when we tried accessing the main site. As it happens, there was a long period (at least 10 mins) when the website just said 'Redirecting. Please wait.' And so I waited as instructed....
Round should be unrated . CF ranking is based on how fast we solve , extending round is not solution . For being fair it should be unrated .
Also i was not able to open m3,m1 too . m2 opened after sometime. I think contest admins are sensible enough to make this unrated .
It was well over 10 minutes for sure
There is no justice in this world.
Round with such beautiful questions goes unrated.
bad luck for me..first time I have solved 4 problems in contest time..but unfortunatly round in unrated :(
So am I :(
Really bad luck for us :(
Same. If there would have been no issues I would have got a pretty good rank than my previous contests.
It is a an amazing round, the problems are really very interesting, doesn't matter if it became unrated. Thanks for the round!
It definitely matters.
I feel like My DP
Indians can relate.
Thats a big bruh.
After round got extended I was confident that round will be rated and I will get my +100 for solving 5 problems.
My disappointment is immeasurable and my day is ruined
true ... i also solved 5 problems and was expecting positive delta then they announced the round unrated
PeopleWithBadLuck++; // same situation
Couldn't you "maintain" the processing speed of the server? I'm looking forward to the next contest.
Me : Having a great round after an eternity
CF : Let's make this round Unrated
same lol ://
Why did the round get unrated? After I got the message "Redirecting... please wait" I immediately went to m1.codeforces.com which was working flawlessly. After that I didn't have any issues. Even if some people didn't know about the lightweight versions, it was only down for 15 minutes (for me), so the 15 minute bonus would solve the problem for them. Would someone mind explaining why the round got unrated? (btw, what a waste, the problems were very cool)
That's true. Actually, I got into m1 after the contest started and, even the main website wasn't working well it was still working perfectly in m1. I can't understand why they wasted time in the main website :(
AC 5 problems and round unrated :(
6 for me :(
AC ALL problems and round unrated :(
AC 3... I am not that unhappy :)
Big heart break after a nice contest, but I appreciate the quality of the problems
fak zis bich
I don't think blog should be downvoted . I don't see how problem setters are responsible for round being unrated . Infact it's sad for them too , their round having good problems got unrated.
From last 2-3 days also, I am experiencing similar technical difficulties during normal problem solving practice. Don't know if the issue is from CF or my ISP.
Lets vote to make this round rated again! Problems are very good, m1.codeforces.com worked perfectly, pls make it rated!
I think once this decision is made it can not be cancelled.
Agree, there is no reason for this to be unrated
Yeah but after announcing unrated in the middle of contest, it cannot be made rated now.
That's not possible.. many of participants would have quit solving already . So , it would be unfair to them .
Btw, admins can make round unrated for that users, which are disagree with their standings, because i tried hard 2h and its unrated((
Yea it is frustrating. But just keep giving contests with consistency :) All the best for the future rounds
It isn't fair for a big number of participants if this round becomes rated and they also took the decision (of making the round unrated) after some delay and discussion. So I don't think it'll be rated again.
P.S. I also wish it was rated coz I also solved 5 problems and had a good rank T — T
Speedforces.
Problem statements were to the point, Thanks for this wonderful round.
Just change the Author to Codeforces...
It is unrated now.
Why this kind of round that has huge difficulty span can be here for us?
I don't understand.
You are right, we don't need this kind of junk to waste 2+ hours on.
Adding 15 mins did enough justice. Should have been rated.
Make it rated please... solved upto E1 but round goes unrated (#sed life)
better luck next time.
Loved the problems! amazing work shishyando and Artyom123! If the round was extended , then I feel there was no need of making it unrated. MikeMirzayanov I feel , this round should be rated:
A) Because m1.codeforces,m2.codeforces,m3.codeforces were working perfectly
B) There was clear instructions given to use the lightweight website
C) There was 15 mins compensation , so basically no (almost no) time was lost
Yes, it should be rated.
Hell yeah
Hope so
I also think it should be rated,there was lots of hard work of writer,tester to make this round,hope to become rated .
No hard work will go in vain. People can still use these problems for practice and learning.
people who wrote "i liked problems" solved only AB and may be C. And they don't know that D and E are garbage...
upd: ok i am sorry D is fine
In fact, I solved E1.But I still like the problems.
Because I want this round to be RATED!
Problems are definitely not good. A and B are fine. But C1 and C2 is a very trivial constructive problem that doesn't meet the difficulty of usual C problems. Also, the only thing you need to know for E1 is prime factorization, I simply don't understand why E1 deserves 1500.
I can't even understand how isaf27 accepted E1... This problem just no idea and nothing interesting
E1 is 1500 point. What to expect? And E2 is kinda nice. No time to implement my idea sadly
E1 deserves only like 1250, if E2 wasn't present it should probably at C in a normal contest.
bruh what? if problem costs 1500 it can be shitty? are you ok?
Isn't it a good pick for C? And normally C is worth of 1500
i think this problem is just bad, and it's position in contest doesnt matter
E1 was free points honestly
E1 is a (maybe simple) math problem.
Agreed, I don't think E1 should be added in this problem set.
Gentle reminder:
The authors did a really good job. And they have nothing to do with the round being unrated.
Please do not downvote this blog. This is just dumping away the authors' hard work.
I don't understand why admins don't make any test-contest of length 10-20 minutes after changes in Codeforces, to check whether server is working correcly or not.
Yesterday Codeforces wasn't availabe for hours, I think that it will be right to make test-contest for not disappointing participants and authors especially.
This was tried by Codechef before. They created an unrated div 3 round after server upgrade but since the round was unrated, very few contestant turned up.
As I remember when Codeforces did test-contest, problems were very easy and around 2000-3000 participants were submitting code after 2 minutes and I think that this is better than doing nothing.
Test contests do not have so many participants. And the reason is not in the number of users. In short, I'm not sure if the issue would be reproduced in the test round.
I just laugh over codechef, in jan lunch time their website didn't worked for half time still they made it rated.
Can't understand why the downvotes to this blog...
It's not the authors and testers' fault but just the problem of the system...
Problem D and E are GARBAGE, that's why this round is unrated.
Even c2 was no different than c1 only one was sufficient
I agree with you.
I just added a line in my code to C1 and passed C2...
I think D and E2 are interesting problems, it's just E1 that was not good.
Could you please tell me how to solve Problem D? I have no idea :(
I have a solution for E2 in $$$O(nkLOG)$$$ with binary search on segtree. Couldn't debug in time. Is it intended?
My pretest passed solution is $$$O(nk^2)$$$.
Thanks for the great contest! Cool problems.
Just had a look at the random solution of C2 and damn. I feel so worthless.
Actually C2 is very easy...
You just need to add one line in the code of C1 and you passed...
At least for me...
Exactly. I did C1 an hour ago and making all type of useless algos for C2. :(
Yup agreed, I was breaking my head for some complicated af solution.
Friends, I apologize that the round was not rated. Please do not downvote the writers. They are definitely not to blame. I figure out what happened. Not very clear yet. We easily hosted noticeably larger rounds. Probably influenced by yesterday's software update. We took advantage of the power outage to update the servers. I am in the process of investigating the issue.
Why problem D was the hardest one?
Their should be a testing round before this contest.
The round was just unrated, it wasn't canceled, so it's not a waste of time.
I liked the problems a lot, but unlike the others I am thankful that you've unrated the contest. There was easily almost half an hour-45 min where even all the three lightweight websites weren't loading. (My internet was and is pretty fast).
Is it just me who cannot access anyone's profile. It shows "The page is temporarily blocked by administrator."
Yeah, maybe to reduce the load.
Such a great round got destroyed. Anyways cool problemset, hoping for smooth conduction of tomorrow's round. Thanks Codeforces!
Автокомментарий: текст был обновлен пользователем shishyando (предыдущая версия, новая версия, сравнить).
Good job to the authors, do not downvote the blog!!! The contest was a little bit Speedforces, but on whole, it was a nice contest. Especially I liked the 2 subtasks, which made the round more balanced. Good job, good job.
OK?
Don't worry, we have one more round tomorrow, give your best!
tfw E1 < B lol
problems were really good overall tho, D was magical because it seemed completely impossible (didn't even know how to solve it without the tag constraint) until I saw the
easy dp
I don't know how to solve D but based on constraints i thought it would be a dp or graphs with O(N^2).
I don't like unrated because of my good performance.
What hurts more than break up....**CONTEST UNRATED** :(
Really disappointed. Went for dinner, when come back found its gone unrated! But they already said we can use m1.codeforces.com if technical issue occurs.** It shouldn't go unrated.**
what are "constructive" problems ? How to get better at these?
My very first contest got unrated :(
I would have hit Master today, but alas, the round got unrated. Still, thanks for the interesting problems.
Please give us one more contest in the span of 22nd to 28th March ;-;
If this round becomes unrated. What is the point of having m1,m2 and m3 server.
I don't think any good reason for unrated.
Many people (including me) didn't knew about m1,m2,m3.
It is your problem. You are a member of cf community for 13 months, messages about m1 m2 and m3 pops up often. During this round there was no period when all of those sites were dead, so nothing was stopping the participants from submitting problems. The round by itself was really good, great thanks to authors and everyone who helped them.
P.S Judging from submissions, many people knew about m1 m2 and m3.
Well I have been an active member of CF from July 2020 (account was created before , but I didn't participated much before ) , and since July I don't remember any moment when we were meant to use M1,m2,M3 , may be there have been pop ups , But I didn't remember them before yesterday , As there are many other things to remember in life than a thing which has very very low chances of happening.
Are the rating changes for this round out ?
wrong post, sorry
Very nice contest! good job.