It's like USACO only with faster results! :)

Wow, finally some Americans.

... There are two 2000 in DIV 1 ! ...
... Maybe I should think twice before decide which one should be attacked first ... )

В анонсе есть две опечатки. 1.Правильно не "Традиционно вы благодарим Gerald за помощь в подготовке соревнования и Delinur за перевод задач. ", а "Традиционно мы благодарим Gerald за помощь в подготовке соревнования и Delinur за перевод задач.". 2.Правильно не "Вы надеемся, Вам понравятся задачи! :)", а "Мы надеемся, Вам понравятся задачи! :)".

Will Фермер Джон and his N коров (1 <= N <= 100,000) make an appearance?

Фермер Джон со своими коровами постепенно захватывают просторы интернета, а особенно USACO и Codeforces)

.

we always see beautiful problems in USACO contests.

I hope we have beautiful and interesting problems in the first usaco-like code forces round !

Good to see Bessie and the cows invading the world of algorithms !

Hi guys, looking forward to round 174.

I wanted to bring up a problem that I found while solving other past problems. The Python language is not very well supported, so that even if a program has the right time and space complexity, it wont pass the tests because the tests have been written with C/C++/Java in mind.

for example I solved http://codeforces.net/problemset/problem/222/B but it would sometime pass and most of the times not pass depending on how many answers I would spit out at a time.

Is it possible to take some actions toward better support of Python? maybe supporting Python3x would be enough cause it has faster input/output libraries.

Please let me know,

pretty good! Good luck to everybody.

many coders from various countries have been holding contests;great!

and I wonder Bessie the cow and John the farmer will cause problems again :)

Counting both Div1 & Div2 , there are One 500 , Three 1000s , One 1500 , Three 2000s but Two 2500s break the sequence :)

Wish I can be red after this contest! I will do my best to help Farmer John to handle his cows!

My time to be pink coder :)

I hate "fading the more negative voted comments" feature of codeforces. It takes me more time to see the comments. I do not why I always open the comments with negative votes(they are interesting and I want to see what people hate and why ??).

Wow, its good.. everyone likes usaco problems and fermer John... So i wish everybody luck :D

will I have to insert "USER,LANG,PROB" headers in my code? :))

It will be produced in usaco's difficulty problems?

The score distribution look's pretty good to me.Wish we have a nice contest! Thank's goes to USA setter scott_wu and abacadaea. We like to help Jhon, Bessie, and cows with so much excitement. :)

В двух предыдущих раундах div 2, задачи "A" были очень легкие и интереса особого небыло их решать. Надеемся тут будут интересные задачи...

Спасибо!

Farmer John? I think I'll back to blue...

memeda

Nice and exciting contest, cute problems! I'm so sad because i couldn't register for it :((

I think they mixed up A and B))

Я думаю они перепутали местами А и В))

Someone else having problem to hack ?

Why i cant hack?

Can't process your hack, try again

Finally see Americans set the problems, good job. Problems in the last contest are way too sophiscated, and this time the problems are beautiful.

I was thinking why codeforces is still in Beta version, Now I know the reason "504 Gateway Time-out".

I was seconds late to submit B :(

Not this time wjmsbmr

Thank you for very interesting problems.

Looks like we beat the USACO results :)

Haven't xperienced too hard DIV-2 A before :\

Now you can see wjmsbmr is not me LOL.

После третьего или четвертого взлома от Egor у меня начали закрадываться сомнения... Примерно после шестого я понял, что мое решение неверное, подумал — "да ладно... все равно я в ж***, так что пусть ломает, перешлю потом, мне не жаль... Если бы не он — я бы вообще не заметил баг..."

Возникло странное ощущение, что я сделал хороший поступок)

На чем все А ломали?

Strongly suggest unrated

Я надеюсь, что не зря использовал в A(div.1)/C(div.2) дерево отрезков с ленивым проталкиванием. Или есть более простые решения?

The Contest was so cool, i like the problems. but i couldn't solve them !!! If i had more time, i would submit problem C too, i solved it but for my internet connection error at the last minute! i couldn't submit it!

by the way, Thank you, scott_wu and abacadaea, for this beautiful problems with cows and farmer John!

First, I got the standard message, that the contest is over. But I didn't send some solution in time, so I entered the contest once again and sent the solution just to check if it was correct (as in 'practice').

And now I see it was sent on 02:04:28 and it was (pre)accepted for judging.

Nice try!

Amazing round ! The problems is interesting :)... But I made a silly mistake again in Problem C...sad >_<

Большое спасибо авторам за задачу A DIV 2 — познавательно!

Probably, first round, when I send solution for A just before contest ends. Thank you for great tasks!

[284C]

#include<stdio.h>
int main()
{
	printf("199999\n");
	for(int i=1; i<100000; i++) printf("2 1\n");
	for(int i=1; i<=100000; i++) printf("1 99999 1\n");
	return 0;
}

Why this generator gives Invalid Input? Please give me a hint. Thanks :)

if(Div.2)

swap(A,B)

... My solution for B(the easiest one) failed because of char mass[100000] instead of char mass[200000] :/ And I was late a little to submit C :/

у двух человек полностью одинаковые решения по 3-м задачам

lawliet_djez : A — 3338474, B — 3334615, C — 3341327.

metalopocalipsis : A — 3338366, B — 3334502, C — 3338081.

Thanks for fast editorial ! Great !

During the contest I didn't read the message about the contest duration had been increased by 5 minutes and I wasn't refreshing my browser after the message had been announced, then on my browser the contest was ended 5 minutes earlier, 2-3 minutes later I had finished my solution for problem A and I didn't submitted my solution because I thought the contest was over :(

on the next round I hope the system refreshing all contestant's browser automatically after the message has been announced

http://www.codeforces.com/contest/284/submission/3335241 and http://www.codeforces.com/contest/284/submission/3334788 are 'quite' similar...

Как все С (div 2) ломали??

Thanks a lot for the editorial just after the contest!

http://codeforces.net/contest/283/submission/3339789 в чем ошибка, скажите, пожалуйстаа

poor system test!

Can someone please help.I was unable to pass the pretests for div 2 problem C . Here is my code. I tried it with segment tree. I'm not experienced with segment tree. I've only used them once or twice.This code got WA in pretest 9.

Amazing round, cool tasks, like it. Thanks guys :)

Sad...I learnt a lesson from this round that I should be more confident..I worked out Div1.D at about 00:15 after the beginning of the contest,but I could't make decision to submit my code because I just think it's impossible for me to solve Div1.D in only 15min..So I stupidly did nothing but waited for someone who would solve it,and it's rng_58 at 00:34,then I followed him and got AC...What a stupid I am huh?

I haven't participated for a while. Can someone please tell me what is "bestRatingChanges"? Is it a new feature?

Can someone explain the solution for Div1 D Can't understand from the editorial

Damn... :( Can somebody share 4 more points with me...? :D

http://codeforces.net/contest/283/submission/3345114 interesting, why does this solution fail on memory? I think I have constant (but big) memory.

Not only the problems were perfect... you have also published tutorials in few minutes... fantastic :)

Does someone know why this solution failed precision check? Does that mean that the sum is wrong and is there a way to download the test?

Can anyone tell why my solution for Problem C Division 2 is gave WA. http://www.codeforces.com/contest/284/submission/3336215

could someone post the test no 10 or help to figure out why my solution on C Div2 fails on test no 10 ?

Yeah~ think my English is very poor ,not you in your problems' discribe.In pro B(div.2),I readed it again again again and again...I dont know what you want to say,I translated it in a variety of dirctions,but when I see the sample input&output,I thought im wrong...

The problems are interesting, it's good to see cows and Bessie again!

it there anything wrong with the checker of div.1 problem A?

http://codeforces.net/contest/283/submission/3331170

i just cannot figure out what's wrong with my submissions, while the checker said "Checker comment wrong output format Extra information in the output file"

Why my actual rank for Round174_div2 is different from the rank that appears on my profile? One shows #5: http://codeforces.net/contest/284/standings One shows #7: http://codeforces.net/contests/with/lxfind There might not be a big difference, but which one leads to the new rating?

My submission for Div.2 C, is giving WA on test 10's 103363rd number due to precision error :(

What a great contest ! I would like to say thank you to figure out my mistake! Expecting you can get great contest later~

I think I have a similar but more comfortable solution for Div.1 D.It depends on this property:

If a[i] has been determined,and a[i-1] should be replaced,then we can optimize a[i-1] that:

Proof:

If a[i] is even,k = a[i] / 2,then a[i - 1] = (2p + 1)k, a[i - 2] = a[i - 1] * (a[i - 1] + 2q - 1) / 2.

Then let r = 2p²k + pk + 2pq - p + pk + q,which is always a integer.

a[i-2]=k(k+2r-1)/2.So a[i-1]=a[i]/2 is better than any other a[i-1].

If a[i] is odd,k = a[i],then a[i - 1] = pk, a[i - 2] = a[i - 1] * (a[i - 1] + 2q - 1) / 2.

Then let ,which is always a integer.

a[i-2]=k(k+2r-1)/2.So a[i-1]=a[i] is better than any other a[i-1].

Using this property,we can calculate dp[i] with simply enumerating j from i-1 to 0.

There are many formulas.Although it's very natural to guess it's correct.The code 3335280 is easy to understand.