Please, try EDU on Codeforces! New educational section with videos, subtitles, texts, and problems. ×

By at1, 10 years ago, translation, In English,

A. Watermelon

Only if w can be presented as 2m + 2k watermelon can be divided to two even parts.
So w = 2(m +k ), where m , k1 , that is
(w 4 и w - even) - necessary and sufficient condition for watermelon dividing.

Read more »

 
 
 
 
  • Vote: I like it
  • +12
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,
Hello, everybody. 

At this point we have already decided on the date of Codeforces Beta Round#5: it's Saturday, March 20. The exact time is still unknown. I do want to find the best time suitable for most participants. Please, express your ideas in the comments - of course, you should not come up with the time that suits only you, but suggest the most suitable time for the majority.  

Wish you high rating,
MikeMirzayanov

UPD.  Thanks to everybody who wrote comments - I've read them all. The venture proved to be useful. Without your help, I wouldn't have been able to take into consideration all those factors which can affect the number of participants.  After much thought, I've made a decision to schedule the round for 19:00 (Moscow time) - I think this option is convenient for most users of the site. It does not mean that we will not experiment with time in future - we will try morning contests, but I can't promise about 5:00:).

Read more »

 
 
 
 
  • Vote: I like it
  • +2
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,
I propose to discuss here the issues and troubles associated with Codeforces Beta Round #4.  On our side, we identified three difficulties: 
  • Slow judging - apologize for the large queue, to the next round, I assume significantly increase the speed of judging;
  • Runtime errors on Python solutions - apparently the decision they want to load some library, which is prohibited by security reasons;
  • Sometimes incorrect runtime errors - apparently the result of the antivirus on testing servers, they will be turned off on the next rounds
Also express your impressions about the round.

P.S. And by the way, the round tutorial is waiting for a volunteer. It is desirable that it will be one of the leaders of today's competition. The tutorial should be in Russian and in English. It will be published on the homepage and later will be available via special link from the contest page.

UPD. The ratings have been updated.
UPD 2. Thanks to KudryashovIA for his help in making contest.

Read more »

 
 
 
 
  • Vote: I like it
  • +6
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,
In email notification (in Russian) I've made a typo. The phrase "It starts on March 12 (Friday), 2010, 12:00" should be read as "It starts on March 12 (Friday), 2010, 15:00 ".

Read more »

 
 
 
 
  • Vote: I like it
  • -1
  • Vote: I do not like it

By Nerevar, 10 years ago, translation, In English,

Dear girls and women! Happy Women's day! On behalf of the Codeforces team I would like to wish you all the best!

May love and care surround you! May you always catch the admiring gazes of men! Stay beautiful and clever and keep making us happy!



Read more »

 
 
 
 
  • Vote: I like it
  • +20
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,
I propose to discuss here all that concerns Codeforces Beta Round #3. Of course, during the competition it is forbidden to write anything about the solution of problems and similar things  

For the time of this contest, we turned off the chat server. This does not mean that it will not operate in future - I think it is a convenient and efficient way to communicate during the competition and you may expect it in the future.  

Also I'd like to announce Codeforces Beta Round #4, which will be held next week. It will be for participants from the second division (non-rated users or those having less than 1500 rating points). We will try not to delay Codeforces Beta Round #5, which will be opened for all. 

Wish you high rating,
MikeMirzayanov

Read more »

Announcement of Codeforces Beta Round #3
 
 
 
 
  • Vote: I like it
  • +6
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,

It seems everyone is in the know that Codeforces Beta Round#3 didn’t take place in the appointed time. Seemingly, it happened because of the increased popularity of the site, on the one hand, and some of our bugs, on the other. For sure, it’s a pity that things went in such a way. On the other part, if everything had failed during the contest, it would have been worse. The contest is rescheduled for Sunday, 15:00 (Moscow time). Please be sure to check here for the start time in your time zone: http://www.timeanddate.com/worldclock/fixedtime.html?&day=07&month=03&year=2010&hour=07&min=00&sec=0&p1=179

I’d like to remind you that the project is in Beta yet, and we’ll work on the problem and try to fix it.

Thanks for your understanding,
MikeMirzayanov

Read more »

 
 
 
 
  • Vote: I like it
  • -1
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,

According to The November Revolution of Colors and Titles, the text below is not an actual and just a historical document.

Not so long ago a new rating system was introduced at Codeforces. To complete the picture I’ll tell you about our Table of Ranks.

From this moment on all the participants will be given ranks that reflect their skills and abilities at such a hard field as computer science and problem solving. Judging by the results of previous rounds you will gain (or lose, I hope it’s not your case) points. If you score big success, you are promoted to a higher rank. You can see the dependence between rating and ranks in the table below. Moreover each rank has its color, which is reflected in the table.

Rating Rank
0-1199Recruit
1200-1349Corporal
1350-1499Sergeant
1500-1649Lieutenant
1650-1799Captain
1800-1999Major
2000-2199Lt. Colonel
2200-2399Colonel
2400-2699General
2700+Marshall

As you have already noticed: we have only three captains in our regiment:  vepifanov gusakov RAVEman. But I’m sure, after Codeforces Beta Round#3 we’ll have a number of promotions.

Wish you high rating,
MikeMirzayanov

Read more »

 
 
 
 
  • Vote: I like it
  • +1
  • Vote: I do not like it

By MikeMirzayanov, 10 years ago, translation, In English,
Codeforces will be unavailable for up to 6 hours while we upgrade our infrastructure (March 3, 4PM - 10PM). Thank you for your understanding.

Read more »

 
 
 
 
  • Vote: I like it
  • 0
  • Vote: I do not like it

By ivan.popelyshev, 10 years ago, translation, In English,

Intro

Every high school or college coach quickly comes to mind about his own online judge system. We can deal with huge systems like  e-judge or pcmc-2 , we can make something our own like contester or acmp , but in any case to create a contest we should

Read more »

 
 
 
 
  • Vote: I like it
  • +12
  • Vote: I do not like it