I have rejudged your submissions at coach mode. And they run as usual. I think you meet a corner case about Codeforces judgement system.

Poor network.... When I finish the coding of A, and click the "submit" button. It costs about 5minutes for downloading the input about 5 MB input. Fortunately, I run and upload as quickly as possibly. I suddenly realize why the problem C has a DP solutions with O(N^3+K) but K is only 5000, not 1e6.

Fixed, thx!

There is no Official Editorial for CCPC-Finals, I will try my best to write the editorial after examinations. But there is official Editorial for China-Finals, I will translate it into English soon.

I have fixed it and rejudged all the submissions. I am very sorry for the wrong data.

AC solution WA solution The differences between these two code are two "cerr<<"s. Is this function change the variable?

Solution my solution for B FST at this test case: 2 15072 South 15072 North The system says the solution outputs a "NO" and expected "YES". I use the custom test and paste my solution and the input correctly. But it outputs an "YES" after running..... Sad story... FLOAT TRAP?

dreamoon_love_AA

That's because the Earth is a sphere. However, I think the time before Russia changed the time zone will be better than now.

That's because div1 C and D share the same full point -- 2000. So it is to say, they think div1C and div1D have the same or similar difficulty.

666 is also a special and popular number in China. When we Chinese see something is so cool or so amazing, we will say it is "666" or "66666666666"(very 666). This special meaning of this simple number begins just in these years. Similar with 666, 233 is another special and popular number in China, which means "LOL" -- Lots Of Laugh. If we Chinese see something is funny or ridiculous, we may say "233" or "2333333333333333333333" (very 233).

I have missed so many contests in 2016 because the power and the internet are always cut off at 23:30 UTC+8 in my school. But this contest is next to the holiday so that I can fight again! I wish I won't forget the feeling of algorithm competitions.

Failed to become Grand Master in 2015......

During the GoodBye2014, I have written a wish that I could become an IGM(rating >= 2600) in 2015. However, now, I have to modify this wish from IGM to GM(rating >= 2400), owing to the rating revolution.

Perhaps they are still busy discussing now? Just wait is OK~

What a large team! Maybe it is the largest team for a contest in CF up to now. Isn't it?

Oh......What a busy weekend!

Of course it won't be postponed. I just complain about the time for me~ However, I am curious for the reason why you disagree with postpone?

Why? Don't you need to go to school or work on Friday?

If it can be postponed for 24 hours, that will much better. Friday is not weekend. Go to school or go to work prevent us from getting up late, even though we participate in Codeforces Contest in the evening.

wiki may help you:[DFT](https://en.wikipedia.org/wiki/Discrete_Fourier_transform_(general)#Number-theoretic_transform) In this wiki, you can see DFT, FFT, NTT. I think it will give you some benefit.

During this contest, I am struggled with div1C. I tried to solve it with two segment trees... However, I have never played with segment trees for months... At last I failed... I think I should train my data structure skill.

Because most of people don't like maths problems, which seems boring in their eyes.

Maths problems is sometimes interesting(brainstorm). But too many maths problems will make my brain feel tired.

Hackerrank is a good place to train myself. However, it cost too much time for a Chinese to open the website.

At first, I have not noticed that the sum of c[i] is not more than 1000... So I think the sum may be as large as one million... I gave up DP and choose factorial numbers to calculate the combination numbers.

Yes... For 250's problem, resubmission = 50 penalty = 50 minutes penalty...

As for 3000's problem, resubmission = 50 penalty = 4 minutes 10 seconds penalty...

In div2, C(div1 A),D(div1 B),E(div1 C) can be solved by maths... C(div1 A) is Combination number. D(div1 B) is Fibonacci number. E(div1 C) is counting the number of bipartite graph. I have solved only these three problems... Therefore I think it is a maths round!

After this contest, it reminds me of an amazing word — aftermath!

A month without div1 and 2 separated contest!

Last div1 and 2 contest was held on May/26/2015 Codeforces Round 305 (Div. 1) Codeforces Round 305 (Div. 2)... I wish we can enjoy your problem set.

Good news. Maybe another cheater is found. You are the 200-th now! Congratulations!

If you have submitted two or more solutions and get pretest passed, only the last time will be system test, and the others will be skipped.

thx

Because of the number of solving users, I have not read the problem statement E and F. And I spend a lot of time for problem C and calculate as more as possible on my A4 papers. However, when I see others solutions for C when hacking, I was shock for the length.

BTW, who can give me some tips or advice to improve my English reading ability in Programming Contest?

Thanks for the contest. This contest shows my poor English reading skill. I spent nearly an hour in struggling with the statement of D. Thanks for the example input and output, and strict pretest of D.

Now it shows your Accepted A.

By the way, it reminds me of lower_bound. If we initial a set in C++, and insert a lot of elements, when we want to find the least one which is larger than x, lower_bound(s.begin(),s.end(),x),O(s.size()), s.lower_bound(x),O(log(s.size()))... The same as map in C++... I have struggled at this problem many times!

It is a good way for me to give up div1A and try to solve B,C first...

If the pretest of div1A can be stronger, I think more people can solve it...

new vocabulary get√

consider maths as my lover

I think everyone knows the story of my username.

"我家妹子不骂人" in Chinese means "my girlfriend will not be angry" in English. and the pronunciation is "wall drug may geo bull mark ren" Here is the International Phonetic Alphabet:/wɔ: dʒʌg mei dʒi bu:l mʌk rən/

Thanks, fixed it~!

#include<stdio.h>
int main()
{
int sum=0;
for(int i=1;i<=1000000000;++i)
sum=(sum+i)%1000000007;
printf("%d\n",sum);
}

This is a code to calculate one billion plus and mod operators between two integers. It spends 3260 ms to solve the correct answer 21 for (1+2+...+1000000000)%1000000007 If you don't output the value of sum, the compiler seems to ignore the calculation of sum as well as the loop, and spends 0 ms. If you delete the mod operator, and change int into unsigned int (that means mod 4294967296)

#include<stdio.h>
int main()
{
unsigned int sum=0;
for(int i=1;i<=1000000000;++i)
sum=sum+i;
printf("%u\n",sum);
}

It costs only 514 ms. That seems that mod(%) will cost 5 times more than plus(+). So it is so hard to say how many operators, because some operators like plus cost little time and some like mod cost much time.

Just read this topic...This Friday, April 17th, 19:00 there will be Round 2 of VK Cup 2015! For all unofficial participants there will be an online mirror that is a usual rated div1-round. Any div1 contestant that does not participate in official Round 2 is able to compete in this mirror.

Here is the official statement

The time is not so good for Chinese Coder... Because such a challenge contest will happen at 0:00 a.m. CST and until 2:30 a.m. CST. Maybe waiting for rating updated until 3:00 .. and 9:00 a.m. CST there is a google code jam Round 1A. I don't want to miss any one...

For all unofficial participants there will be an online mirror that is a usual rated div1-round

Two records, congratulations!

Wish you can rating-up again and become master soon~

How to minus them. The blog of April Fool Day contest has been deleted...

gay....do you mean "guy"?....

Wait for a div1 round for a long time! I can't wait any more!

No English problem set?

The number for the order seems to be in a mess?

I remember that the limit of upvotes is 999~ it seems it will become true soon~ Congratulations for the record !

You are a skilled competitors too! You solved 3700+ problems in Codeforces and participate in 122 contests so that you are an experienced competitor. Your rating can show that you are one of top competitors.

Therefore, you are a skilled competitor.

Amazing Ending!

2nd again= =... because of so many FST for B... the score of B change from 500 to 1000...

I think he/she can pass system test safely!

UPD: although he/she pass system test... It is surprising that so many FST on B, therefore, the score of B level up from 500 to 1000~~~ rank change!

You should change the names on the back of the clothes~

Tonight YuukaKazami cgy4ever tourist I_love_Tanya_Romanova all registered div1.

It is my first Spring Festival's Eve with coding~~~ Amazing night!

It is impossible. He has no time for this...

If it is a group of five users from top 30, I think the score of Codeforces Round 284 (Div. 2) may be higher. I think two or three users will be possible.

Because 3 minutes(147 seconds) for div2B and 3 minutes(183 seconds) for div2C(div1A) is an amazing speed for reading statements and coding if it is single!

I think you can make the prime in hash be a variable P. Then you prepare hundreds of different primes and make a table of them, when the program begins, it choose P randomly from the table. I think no one can hack you, or your program has some bugs out of hash.

I test your hack case and the code in my computer. I find that it cost 9 seconds in my computer! So I think the Online-Judge in Codeforces is very very fast.

I think a prefix tree can be considered as a set of string(if we add a counter, it can be a multiset or map), and it can find whether a string is in the set(prefix tree) in O(length). I think it is correct.

For the first question, the complexity is O(Llogn)... Because in the set<T>(T is a kind of type), we should give the way to compare two Ts, which means we should provide a function like bool operator<(const T&a,const T&b)const; However, the comparing function between two string is provided by #include<string> and it is O(L)

And the second question, in order to compare correctly, the comparing function provided is comparing char by char.

ACM-ICPC rules is ranked by time and the solved number... What about the score?

But UPD2: Scoring will be 500-1000-1500-2000-2500-3000. it seems to be a Codeforces-rules~~~

Of cause not, none of the contest in gym is rated.

You can use "cout" for long double...long double is not prepared in printf/scanf

Sigh...When I read this problem statement and realized it can be solved by maxflow, it was 5 minutes left... I spent(wasted) too much time on G3. I thought of the matrix all the time.

As you expected, tourist got the iphone6~

The possibility will be stable.... I tried to find the matrix A for dp(n-1)*A=dp(n).... But failed.

Amazing! I have seen that at the same time there are at least 50 submissions judged! (Because there are only 50 submissions in one page...) How fast!

I remember that I saw Round 288 div.1 && div.2 about 5 days ago. But now there exist only div.2...Could I ask the reason why the div.1 is cancelled? Is it because the problems for div.1 are not prepared?

The difficulty of the problems are very hard to judge...

9373166 was sent at 2015-01-06 17:07:40

7687485 was sent at 2014-09-05 14:42:28

How can a user copied a solution from the future!!!!

If you know please tell me, I want to copied the source codes of windows 11,IOS 20 and Android 6.0!

I want to change my handle... But I haven't found anything more interesting for me than maths... Even coding, algorithm, acm.... I am learning those for maths.... So this year I give up changing my handle again...I wish Codeforces will attract more coders in the 2015!

And at last, you got Accepted~ Congratulations~

Many participants solve B by Floyd... I think E should be New Year and Maths once more

First positive up votes from the beginning....What's the matter? I am curious about it.

OK. That is to say, the problems are designed for single participant. What an excellent to begin a year by participate a contest! I hope I have no exams on that day.

It is team participate or single participate or both? I remember the contests in gym can be participated by team of three users

How hard it is!!! Poor rating...

Good Luck to you two!

if the hack points is defined by short, he can do it... if it is int..I think codeforces may break down.... if long long...the internet of the world may break down..What a DDOS!

wait for 15 hours and you can see those.

So I am curious that what dreams do you have?

He is so cool yesterday... I admire him very much and he is my hero!

My score in this year's regional contests may surprise you.... Because I haven't got any medal! ...... I thinks I should change my training way in the later year....

It is impossible to become International Master even you are rank#1 yesterday, but you become master again... Good job!

And I get a lot of down votes.......I feel sorry for those...

aha~because at that time, I dream for candidate so much... and the black days make my rating roll back to specialist again... I was so crazy at that day...

I wish you can become Grandmaster tonight! World Final kuangbin!

Best wishes! Good Luck && Have Fun!

I hope this contest will bring me from unhappiness...... I even suspect whether coding is suitable for me...