Dear CodeCheffers,
We are back again. The CodeChef judge is up and working now. You can continue making your submissions. We will keep you updated on the extension of the contest. We sincerely regret the inconvenience caused.
11/03/2011 15:00 (IST) UPDATE: Contest will end temporarily and will be restarted for 24 hours as soon as we have our Judge up and running. We sincerely regret the inconvenience caused.
12/03/2011 14:20 (IST) UPDATE: CodeChef judge is back up and running smoothly. You can continue making your submissions. For people participating in the March Challenge, we will let you know about the extension of the contest shortly. Please check our announcements page for any updates. We regret the inconvenience caused.
– tojo
Hi CodeCheffers,
At the beginning of the year we announced that we would be implementing a brand new rating system for our Cook-Offs. Unfortunately its launch was delayed as we were busy tweaking and fine tuning the parameters in our algorithms to try and improve the new rating system into its best possible version. We wanted to make sure that the rating system that we put up is as good as it gets! A lot of of you have been patiently waiting for the implementation and we apologize for this delay.
Its time for good news now. 
The moment has finally arrived! Our new rating system has now gone live!
It is available at the link .
The contests that have been affected by this are COOK01, COOK02, COOK04, COOK05, COOK06 and COOK07.
COOK03 has not been rated as it was a team based contest.
The rating will only apply to contestants that have made at least 1 submission during a contest.
For more details about the rating system please take a look at our earlier blog here.
If you have any feedback or opinions that you would like to share with us about this new system the feel free to write in to feedback@codechef.com or putting up a comment below this blog post.
Regards,
Vishal
Dear Contestants,
Considering the issues that occurred in the recent contests, we have implemented a new notification feature on CodeChef. In the last short contest some of you were unaware of the changed problem statements and as a result had to suffer with unwanted penalties. While we understand that such scenarios should be best avoided and we strive to eliminate them completely, yet at times we do end up making mistakes. However, to notify all the users instantly is the least that we think we can do to make it fair to all.
As per this new feature, whenever there is an announcement made in any contest or when the admins want to notify you of some event, every logged in user will get a notification in the form of an alert box.
Regards,
Vishal
PS: We are testing this feature on the website for some time. For this reason you may see an alert box while browsing CodeChef.
Dear CodeCheffers,
At the onset of this new year we are gifting ourselves a new calendar on CodeChef to keep everyone updated on important programming events. If you think we have missed any event please comment on the page to get them added to the calendar.
Have fun,
Tojo Chacko
Hi guys,
We’re finally in the middle of Christmas season! A time for fun and joy and also giving each other lots and lots of presents! Our chef is always excited at this time of the year and cannot wait to reveal his gift for you all.
Are you all ready? *drum roll* With the new year will also come into place our brand new ‘Short Contest Ratings’!
Check out the salient features of our very exciting rating system :-
1. The ratings will take into account COOK01, COOK02, COOK04 and COOK05. COOK03 will not be considered as it was a team based contest.
2. A player will be rated (awarded rating points) in a contest if she has made at least one submission in the contest. If someone doesn’t make even a single submission in the contest then her rating will not change after that contest. (note that it may bring down her rankings).
3. It will be a seed based rating system modeled on the ELO rating. Reference – http://people.ksp.sk/~misof/publications/2009thesis.pdf page – 22.
4. The rating algorithm is a function which takes 2 inputs in the form of Ratings before this contest and Ranks in this contest and gives the final Rating as output. If a contestant participates for the first time in a contest then her previous rating is taken as some default value (say 1000).
5. Mathematical details of the algorithm are described here in brief :-
First for each pair of players (A,B) we calculate the probability of A defeating B and vice versa based on the ELO formula. Then for every player we calculate the sum of probability of defeating other players.
Lets say,
P[B, A(i)] = probability that B defeats A(i).
total[B] = summation of P[B][A(i)] over all A(i).
n = number_of_participants.
The expected rank of a player B in a contest,
E[B] = n – total[B].
We define regular factor for contestant B,
Regular_factor[B] = E[B] – Rank[B].
We have also added a bonus factor so that we can reward extra points to players who have been ranked higher in the contest.
bonus_factor[B] = n/rank[B].
Then for each participating contestant her rating is modified as follows:
New rating[B] = rating[B] + k * regular_factor[B] + m * bonus_factor[B].
Here k and m are constants to give appropriate weight to both the factors.”
Do send in your feedback and let us know what you think of this new rating system for short contests. We hope you are as excited about it as we are!
Best wishes for the new year to you all!
Cheers,
Team CodeChef
Hi everyone,
We have introduced a new challenge tab in the practice section wherein all the challenge problems will be listed. This enables you to find all the challenge problems in a single place without browsing through the other categories. All the challenge problems that belonged to the previous contests have also been added to this area.
Cheers,
Tojo
Our Mail System was down and registrations were stuck. The issue has been resolved. Please use “Login | Forgot Password” to get the password mail again. If you are still facing any issues please mail to feedback@codechef.com. The inconvenience is deeply regretted.
Cheers,
Vishal
Update: The site is up and running now. Thanks for your patience.
We are taking the site offline for a couple of hours for some maintenance activities. We will be back soon.
Thanking You,
Vishal Anand
Hi guys,
UPDATE: The site is up and running now. Thanks for your patience. We have upgraded the site for better performance. However, if you face any issues please report to feedback@codechef.com.
We will be taking CodeChef offline for about 4 hours from 00:01 IST tonight (1st October). This is to carry out some maintenance work on the site. We will be back in a while and will come back better rejuvenated at that.
See you soon.
Regards,
Team CodeChef
The Indian Institute of Information Technology, Allahabad, India cordially invites you to be a part of online programming contests,Alkhwarizm and Limite-De-Plazo, organized as a part of our annual fest, Effervescence.
These programming contests are brought to you in partnership with the Directi Go for Gold Initiative.
Alkhwarizm will start on 1st October , 7.00 pm ( GMT +5.30 hours) ( Other Time Zones )
Limite-De-Plazo will start on 2nd October , 7.00 pm ( GMT +5.30 hours) ( Other Time Zones )
Total prize money for Al-khwarizm and Limite-de-Plazo is 35,000 INR ( $775 ).
For registration please visit either of the links
Cheers!
Team CodeChef
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