Всем привет!
Совсем скоро, 20 ноября в 19:35, состоится Codeforces Round #332 (Div.2), автором которого являюсь я. Это мой второй раунд и я надеюсь, что не последний.
Спасибо Дмитрию Рожкову (rui-de) за прорешивание раунда и подготовку задач, а так же Владу Вишневскому (Vladik) за красивые картинки к задачам. Большое спасибо Глебу Евстропову (GlebsHP) за помощь в подготовке раунда. И, как обычно, спасибо Марие Беловой (Delinur) за перевод условий на английский язык и Михаилу Мирзаянову (MikeMirzayanov) за замечательные системы Codeforces и Polygon.
Контест будет длиться два часа. Что касается задач, то ни для кого не секрет, что на дне океана есть ананас Губки Боба и ресторан "Красти Крабс", уютный пляж и Медузные Луга ... Но Губке Бобу и его друзьям понадобилась помощь, помоги им!
Настоятельно рекомендую прочитать все задачи. Надеюсь каждый найдет себе что-нибудь по-вкусу.
Как обычно, разбалловка будет объявлена позже.
UPD: Разбалловка выглядит следующим образом — 500 — 1000 — 1500 — 2000 — 3000
Div. 2 Winners
Div. 1 Winners
Congratulations!
Вы готовы дети???
Да капитан!
this round will be easy
Problem A was so easy http://mirror.codeforces.com/contest/599/submission/14491944
уши почисти
ииииииииииииииии
First problem be like:
Spongebob and Patrick like to light fire under the ocean when it's cold! ...
Spongebob was developed for mentally retarded children..
There are many hacks in this contest.
And there are many wrong answers on main test too I didn't join the exam but i see "Wrong Answer on Main Test" when i check somebody's wrong code...
Наконец-то время сразу правильное указали.
I won't see SpongeBob anymore if I lose rating in this contest :/
** And you're the reason Yury_Bandarchuk :'( **
UP: I won't see SpongeBob anymore :/And you're the reason Sa1378 of your rate loose!
В текст поста вкралась ошибка.
Совсем скоро, 20 ноября в 19:35, состоится Codeforces Round #322 (Div.2)332
теперь мы знаем любимую игру автора, спасибо Фрейду.
Твою тоже знаем.
Good way to celebrate children's day :D
What a nice idea. Good luck to everyone
Good Luck All ^_^
is it only me who hasn't seen SpongeBob? :P
you are not alone :p
no, me too
Картошечка))
Not sure if it's codeforces or cartoon network
Did you mean Nickelodeon? :P
yup my mistake :p , i'm not a big fan of cartoons .
It is Codeforces just probblemsetters adding this pictures(or cartoons pictures) just for fun.It is more enjoyable for coders!
Especialy when you have to wait longer to download 1st problem
i hope short problems statements :)
Time shedule change. Today's contest time 19.35 . I hope next contest time 19.35(1/2).
Never go full retard.
:D
I love Spongebob and I hope " I love this contest " too :D.
Two Future Contest already Announced , So Nice :)
Thanks to autors for Round!!! Good luck all contestants
Spongebob is love, Spongebob is life. This contest's gotta be good.
Someone dare to say "I hope Spongebob dislikes math?"
(Downvotes swarm incoming...)
If he dislikes maths, he'd ask you to solve his math problems. If he loves maths, he'd be too busy and he'd ask you to solve his math problems. It's maths either way.
Oh God... Codeforces should restrict such big images.
Yah :) A coding month :) Really love it :)
Yah :) A coding month :) Just love it :)
Have a nice evening and good luck everyone~~~
if you see this coment and you will have a increase of rating！you Konw I am lucky star!
If not then better rating next time. :)
Wish Mr.Plancton doesn't have a evil plan for your rating! good luck all CF members! :))
Are you Bohdan Pryshchenko or his opponent?
Unfortunately, I'm not Bohdan Pryshchenko and also i'm not his opponent! I even don't know him, and I chose this handle because I recently got to know this site, and I don't have an idea for a cool handle, so I choose this (I see I_love_Tanya_Romanova in the top contributors list)!
I mean Div.1 in new profile :)
Let's see if I reach div1 :|
is it spongebob photo album or round announcement ?
I guess it's spongebob photo album :)))
P.S: plz correct "spongebob" in your comment :D
Why late 5.00000 minutes.
MVP?
http://knowyourmeme.com/memes/events/kevin-durant-mvp-speech
Obviously, it is Minimum Viable Product
what about scoring distribution?
As usual, scoring distribution will be announced after the contest.hahaha.......
whisper: if you change language you will see.
Forgot to register, NOOOOOOOOOOOOOOOOO!
wish you a high rating in this contest :D
You do it wrong... nooooooooooooooo
What is scoring distribution?
Spongebob and his stupid friend Patrik are here to challenge us quite interesting!!! :-)
When do you want to announce the scoring distribution?contest is starting :|
It was published in Russian version of the post, but the author forget to add it to English one.
When are you going to remove Russian Codeforces?
Why would we do this?
To save the amount of work and reduce the level of confusion. Besides I've heard some time ago that Russian CF was supposed to be removed.
Good problems!!!
What was hacking test of prob B?
wish I knew it :(
It's difference between Ambiguity and Impossible. Example
3 3
1 2 1
3 3 2
Will give Impossible but your code maybe giving Ambiguity.
2 2
1 2
1 1
->
Possible
1 1
2 2
1 1
1 2
->
Impossible
I think if the case is "Ambiguity" and "Impossible" at the same time, it should be "Impossible".
Actually I just realized that
should give "Possible". I'm printing "Ambiguity" even if the b sequence doesn't use the ambiguous key.
In that case when answer is possible but you have printed Ambiguity even it is not appeared in B.
3 3
3 2 3
2 2 2
I used this
Most of the codes (including mine) give "Ambiguity". But the correct answer is "Impossible".
PS — I hacked 3 codes using this test case.
Edit: C has more successful submissions then B :| :|
No need for sort.
3 3 3 3 1 3 3 2
Answer?
Impossible
Anyone else got WA #16 for E? I am really curious about that test case.
Orz
Классный раунд, за 3 минуты до конца придумал тест на B, и начал ломать всех подряд, и вы знаете, +7 -11, не смотря на коды
Интересная была задача B. Я её перепосылал, когда уже прошло полтора часа...
Поскольку в В может быть такая ошибка: многие выводили Ambiguity в цикле, а там, дальше, могли идти значения, дающие Impossible.
Контртест:
Ответ: Impossible (не Ambiguity).
ну я просто понадеялся на опасный случай, когда всем даётся одинаковый номер(Possible, не Ambiguity), то есть
3 3 1 2 3 1 1 1
Is D all about a cubic equation?
Yup. Wish I clicked on it sooner. I clicked on it literally 2 minutes before end. Couldn't solve C, or B.
Solved the problem D 2 sec late hope my solution idea will be wrong. Edit: Solution is wrong:)
chrome не сдаётся!
This always freaks me out before realizing that System Test hasn't got to my correct submissions yet.
Yes this happened with me too. :D
after this contest i will never see Spongebob :((
Nice problems, superfast editorial and superfast system testing! This contest can't get any better! :)
Nice problems, superfast editorial and superfast system testing! This contest can't get any better! :)
Thank you so much!
The first problem is what is needed. You first submit obvious solution and then realise, that there are tricky situtaions.
Thanks to GlebsHP too. :)
Problem B isn't written well, I don't understand it until now
No it's written perfectly well, and it's crystal clear.
Number of AC solutions in B indicates that there is something wrong only 1100 AC solutions in B is a very small number compared to previous contests
It's because the pretests were a little weak.
Look again
Well, counting the solutions AFTER the contest (i.e. all the people who fixed their solutions and submitted) is really dumb.
Go here and turn unofficial results OFF, and you will see that B was solved by 984 participants while C was solved by 1043 participants.
Indeed, the rule about Ambiguity > Impossible was not clear.
The statement says "(...)If there are multiple suitable sequences ai, print "Ambiguity".(...)"
When the answer is "Impossible" the number of suitable sequences is 0.
My first solution for B was hacked but I must admit that the statement was clear, the problem was my lack of attention.
I think that the low number of AC's was due the difficulty of the problem, it's harder than expected for B.
Sorry, I didn't know that. After all, I am a mere Pupil. :)
f is a function means that the ith f equals to f(i),so bi=f(ai). And I was confused too. But problem B is nice.
It's well written. It's just tricky. I got hacked and I couldn't figure out my mistake during the contest. Turns out it is wrong to immediately print "Ambiguity" after finding more than one such index. This is because at such point, it is still possible for the answer to be impossible, i.e. there exists no such sequence a.
Жаль rakhashov.maksat, ведь он единственный решил все задачи(Единственный решил Е), но остался на 2ом месте. Либо сам виноват, что сдал А с 3ей попытки, либо jerjerismygf молодец, так как сделал 18 успешных взломов
Не, все норм. Просто Е-шку с первой попытки надо было сдать :)
Кстати не знаете почему за А +2, если должно быть +1 т.к. у вас первое решение сломалось на 2ом тесте, описанном в условии
Не штрафуют только за ошибку на первом тесте.
Вообще-то крайне подозрительно, что он сдал все 5 задач, с учётом того, что на предыдущих шести раундах этой осенью он и одну-то, первую, задачу не всегда мог сдать.
просто для того, чтобы произвести впечатление, посмотри на latisel, он несколько раундов решал всё и делал 200+ неудачных взломов, чтобы понизить рейтинг. думаю rakhashov.maksat пошёл тем же путём, только без взломов.
P.S. В Div1 просто нынче тяжело, вот люди и не хотят туда переходить.
Что-то непохоже. В первых пяти раундах по пять неверных попыток по задаче А, либо сданная А и несколько неверных попыток по В, а в этом раунде всё довольно чисто, особенно сложные задачи. Да и стиль кода совсем другой в этом раунде.
Ilona Inc.
Got Runtime Error in test case 33 for Question C. But, my program is able to solve problems for higher n without runtime error. How is it possible? http://mirror.codeforces.com/contest/599/submission/14373631 Sorry found the mistake.
Interesting round! "weak" pretests, many hacks at the end :)
Bad contest :|
Good contest, fun and educational.
But...But anta last visit at 25 hours ago
Codeforces API?
I solved problem A. But my rating is not changed. It is my first contest, help me please....
Please Wait
why is still system testing for me and can't submit anything, but number of accepts is getting more and more?
You are not alone, so silly things are happening right now..
WTF???
Ratings changed but I still can't submit...
And also there isn't any friends rating changes in standings.
Mine is still at system testing too.
Ошибка в подсчете количества решенных задач.
UPD: Исправлено.
For problem D
for(i=2; i<10e6; i++) : WA65
for(i=2; i<2*10e6; i++) : AC (after contest)
:( my calculations gave cube_root(x); it turned out to be 2*cube_root(x);
you must do it to 1442251, because it can be ans for x around 1e18
A gray participant who solved all 5 problems. Just wow.
Div1 player dude
Didn't expect such a good problemset from the fan of the cartoon for idiots.
I had a really good time, thank you! Look forward to see your next contests!
Cartoon for idiots?
I loved Sponge Bob when I was a kid.
So what?
I loved Sponge Bob when I was a kid.It means you don't love him anymore? How could you??
Agree, Grendizer FTW!
D was much easier than B & C.
B is easy too, C is the bomb.
B was easy but tricky. D had no tricks ;)
A,B,C,D easy, E hard
C was the trickiest of b,c,d. Spent all my time on it, and kept coming up with test cases where my solution would fail,before time was up.
I'm sad to get WA on test 65. I'm extremely sad that there isn't test 66 after I accepted it! :(
Congratulation rakhashov.maksat for solving all five problems. From today you are my new inspiration :)
From today (s)he is my favorite troll :)
I am also surprised to see his ranks. How it possible ? In CF round 325 he was newbie, But in 332 he collects 535 rating. What occurs in last 7 contest for him ?
Кстати, рановато победителей объявили, системное тестирование-то всё ещё идёт.
у меня примерно через 15 мин после сис тестирования появилось, всё норм вроде
easiest contest i ever solved
That moment when u are confused about ur own solution's time complexity...
Submitted it assuming it to be O(sqrt(x))(expecting TLE)
but it was O(cuberoot(x))
a confusing loop:
for(i=1;i*i<=x && (x/(i*(i+1)))>=(2*i+1);i++)
(x/(i*(i+1)))>=(2*i+1) ---> x>=(2*i+1)*(i*(i+1)) Now it's not confusing ;)
Yesterday I was 16 and today I am 17.
Yesterday I was expert and today I am candidatemaster.
Come on!
btw nice graph ;)
On the proble C: Tests was less than need. That is cod TL 14376989
That is generator which it kod get TL
include <bits/stdc++.h>
using namespace std; int main() { int n = 100000; cout << n << "\n"; cout << n << " "; for(int i = 2; i <= n; i ++) { cout << i — 1; if(i != n) cout << " "; } cout << endl; }
why it's "Practice is allowed only for finished and unfrozen contests"?
I have this problem too . what should we do !? UP : It's fixed now (at least for me !)
У меня в firefox нет таблицы с рейтингом. У друга в chrome есть. Почему так?
+535 New Record Oo
Here is my vision of the problem A.
By any means we should get to the
Shop 1. How many ways to do that?1. Paths to
Shop12. Paths to
Shop23. Now, get back
Home:)And the code looks like this:
I've solved just A. But I hope that at least I could be helpful to those who struggled with it :)
It might have been more fun to make pretests for A weaker. I actually thought about only two situations at first, but I realized that there were another two, not using either the path to A or B. It was kinda tricky. But the problem B also had some hacks, so... NICE CONTEST!!!
Also jellyfish for the next time...?
Any thoughts, when will we get a tutorial for this contest's problems?
Its already there. Check editorial link