The International Olympiad in Informatics is one such event that we all look forward to, not only as players but also as spectators. An annual competition that began in 1989 in Bulgaria, the IOI has risen from its humble beginnings to become one of the largest worldwide competitions for school students that tests their skills in programming and problem-solving.

CodeChef is conducting the next replay of the Indian IOI Training Camp. This contest is the second among the three replays that we plan to conduct. There will be three challenging problems and a five-hours to solve them.

The authors of the round are:

• Kushagra Juneja (kushagra1729), Praveen Dhinwa (PraveenDhinwa), Sreejata Bhattacharya (AnonymousBunny) and Zi Song Yeoh (zscoder)

The testers panel consists of:

• Rajat De (rajat1603), Sampriti Panda (sampriti), Sidhant Bansal (sidhant), Arjun Arul (arjunarul), Swapnil Gupta (born2rule), Sreejata Bhattacharya (AnonymousBunny), Animesh Fatehpuria (animeshf), and Arjun P (Superty)

How to participate? It’s simple, just register at CodeChef if you haven’t done so already, and check out the details below! We hope that you will find the contest very interesting. We wish that you will enjoy the round as much as we enjoyed preparing this round.

Start Date: Saturday, 21st July, 2018 at 19:00 HRS (IST)

You may check your timezone here.

Contest Link: www.codechef.com/IOITC182

Good luck!

Cheers,

Team CodeChef

Competitive Programming is all about the thrill of pitting yourselves against other coders and seeing who comes out on top. And in general, there’s nothing quite as fun for our community as putting on our coding hats and flexing our fingers over our keyboards and getting down to solve an interesting problem.

But competitive programming, like every sport, also has its World Cups. And for the CP community, the International Olympiad in Informatics is one such event that we all look forward to, not only as players but also as spectators. An annual competition that began in 1989 in Bulgaria, the IOI has risen from its humble beginnings to become one of the largest worldwide competitions for secondary school students that tests their skills in programming and problem solving.

Only the very best make it to the IOI Training Camps and eventually, the finals. Many of us have always wanted to see what the competition is like but the chance is given only to a select and deserving few. Fortunately for the entire community, CodeChef is bringing the Indian IOI Training Camp experience to you on our platform.

So what is an Indian IOI Training Camp? The Training Camp is probably one of the most enriching experiences any competitive programmer can have. The camp has two aims : it narrows down the pool of participants from a country from around 30 to 4 final participants, and it also trains and tests the participants so that they are ready for the big stage.

And it is this test that CodeChef is bringing to you. We are conducting a replay of the Indian IOI Training Camp, in the same format. There will be three challenging problems and a five-hour time limit for solving them. Three Team Selection Tests were conducted in May for the selection of Indian IOI team. This contest is the first among the three replays that we plan to conduct.

We’re sure you’re as hyped about this contest as we are. How do you take part? It’s simple, just register at CodeChef if you haven’t done so already, and check out the details below! We’re looking forward to seeing you all experience the thrill of the Training Camp selection tests.

The authors of the round are: - Arjun Arul (arjunarul), Praveen Dhinwa (PraveenDhinwa), and Sidhant Bansal (sidhant)

The testers panel consists of: - Rajat De (rajat1603), Sampriti Panda (sampriti), Kushagra Juneja, Swapnil Gupta (born2rule), Sreejata Kishor Bhattacharya (AnonymousBunny), Animesh Fatehpuria (animeshf), and Arjun P (Superty)

Duration: 5 hours
Start Date: Friday, 22nd June, 2018 at 19:00 HRS (IST)
End Date: Saturday, 23rd June, 2018 at 00:00 HRS (IST)

Contest Link: https://www.codechef.com/IOITC181

The time in other timezones can be seen here

Good luck!

Cheers, Team CodeChef

Hello CodeForces Community!

The 2018 edition of the 24 hour programming marathon, Deadline24, is a unique contest featuring non-stop programming action and challenges. Now, you can step up your preparations for it by taking part in the replay contest of the 2017 Deadline24 Qualifying Round.

Here are the contest details:

Time: 9th February 2018 (2030 hrs) to 9th February 2018 (2330 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Contest link: https://www.codechef.com/DEAD2018

Registration: This is a team contest. Therefore, those interested must register here
(https://www.codechef.com/teams/register/DEAD2018) in a team and have a CodeChef handle to participate.

All those who do not have a CodeChef handle are requested to register in order to participate.

Happy Programming!!
Enjoy the round!!

Greetings from CodeChef!

We would like to extend our invitation to you for participating in the ACM-ICPC Amritapuri Onsite Replay Contest and solve the problems featured at the ICPC Asia-Amritapuri Onsite Regionals.

Contest Details: Time: 3rd February 2018 00:00 hrs — 4th February 02:00 hrs Indian Standard Time — +5:30 GMT) — Check your timezone.

Authors: GlebsHP (Gleb Evstropov), Vaibhav Tulsyan, PraveenDhinwa (Praveen Dhinwa), Balajiganapathi S and Akashdeep Nain

Testers: mgch(Misha Chorniy), Animesh Fatehpuria, Triveni Mahatha

Contest link: https://www.codechef.com/AMR17ROL

Registration: You need to have a team and a CodeChef handle to participate. Team Registration Link: https://www.codechef.com/teams/register/AMR17ROL. For all those who are interested and do not have a CodeChef handle, are requested to register in order to participate.

The problems are super interesting and I am sure you all will have a great time while solving these :)

Good Luck! Hope to see you participating!

Hi Friends,

Greetings from CodeChef!

I would like to invite you to participate in the ACM-ICPC Kolkata-Kanpur Onsite Replay Contest and solve the same problem sets faced by contestants at the ACM-ICPC Kolkata-Kanpur Onsite Contest.

Contest Details: Time: 27th January 2018 00:00 hrs — 28th January 02:00 hrs Indian Standard Time — +5:30 GMT) — Check your timezone.

Contest link: https://www.codechef.com/KOL17ROL

Registration: You need to have a team and a CodeChef handle to participate. Team Registration Link: https://www.codechef.com/teams/register/KOL17ROL.

For all those who are interested and do not have a CodeChef handle, are requested to register in order to participate.

Good Luck! Hope to see you participating! Happy Programming !!

Hello Friends!

I would like to invite you to the ACM-ICPC Gwalior Replay Contest, which will give you a chance to solve the questions featured in the ACM-ICPC 2017 Gwalior Onsite Regionals.

Contest Details:

Time: Saturday, 20th January 2018 00:00 hrs — 21st January 02:00 hrs Indian Standard Time — +5:30 GMT), Check your timezone. Total 26 hours long.

Contest link: https://www.codechef.com/GWR17ROL

Registration: You need to be registered with a team and have a CodeChef handle to participate. Team Registration Link: https://www.codechef.com/teams/register/GWR17ROL.

For all those who are interested and do not have a CodeChef handle, are requested to register in order to participate.

Editorials will be provided right after the contest.

Good Luck!
Hope to see you participating!

Hearty Greetings!

I invite you to participate in the ACM-ICPC Asia-Kharagpur Onsite Replay Contest, which will feature the same problem sets faced by contestants at the ICPC 2017 onsite regionals.

Contest Details:
Time: (Saturday) 13th January 2018 00:00 hrs — 14th January 02:00 hrs Indian Standard Time — +5:30 GMT) — Check your timezone.
Contest link: https://www.codechef.com/KGP17ROL
Registration: You need to have a team and a CodeChef handle to participate.
Team Registration Link: https://www.codechef.com/teams/register/KGP17ROL.

For all those who are interested and do not have a CodeChef handle, are requested to register in order to participate.

Good Luck!
Hope to see you participating!

Hi All,

ACM ICPC Chennai, India regional replay is running on CodeChef. You can participate in it as a team at https://www.codechef.com/CHN17ROL. Please note that it is a team contest. The contest will end at Monday 2 AM IST (around 33 hours from now).

NOTE: The contest has been extended by one day.

Happy programming,

Regards,
Praveen Dhinwa
Team CodeChef

P.S. Sorry for a late announcement :(

Hello Codeforces Community!

I would like to invite you to CodeChef July Challenge 2017. It begins on the 1st Friday of the month and it will go on for up to 10 days. It would give you a good amount of time to solve the problems.

Joining me on the problem setting panel are: abh1906 (Abhinav Jain), kingofnumbers (Hasan Jaddouh), arjunarul (Arjun Arul), PraveenDhinwa (Praveen Dhinwa), Fekete (Ivan Fekete), adamant (Alexander Kulkov), chemthan (Trung Nguyen), Errichto (Kamil Debowski), AlexandruValeanu (Alexandru Valenu).
Editorialist: Pepe.Chess (Hussain Kara Fallah)
Testers: mgch (Misha Chorniy)
Russian Translator : CherryTree (Sergey Kulik)
Mandarin Translator: huzecong (Hu Zecong)
Vietnamese Translator: VNOI Team
Contest link: https://www.codechef.com/JULY17

Please feel free to provide the feedback about the problems in the comments.

There is no registration required, anybody with a CodeChef handle can participate. Top participants can win CodeChef laddus (details on the contest page).

You will be provided 10 problems.
On top of all it promises to deliver on an interesting set of algorithmic problems with something for all.

Good Luck! Hope to see you participating!!

Hello CodeForces Community!

The SnackDown 2017 Finale is tomorrow and the mood here in Mumbai is wonderful. All the teams here seem excited for the final contest.

In parallel to the SnackDown 2017 Onsite Finale, there will be a mirror contest of the onsite finale and I’d like to invite you to participate in it. The CodeChef SnackDown 2017 Onsite Final Mirror will begin at 12:30 IST of 1st July 2017 (check your time zone here and will last 5 hours.

Registration: You can register in a team of two or can go solo into the contest. Please visit the following link to register: https://www.codechef.com/SNFL17MR

See you all at the contest!
Regards,
Praveen Dhinwa Team CodeChef

Hello CodeForces Community,

In the recently concluded SnackDown Pre-Elimination Round A, we have seen participation from over 9K teams. In total, 1469 teams who were under top 1000 ranks in the Pre-Elimination Round A have been moved to the Elimination Round and we are now ready for the Pre-Elimination Round B. The qualified teams will not be participating in the Pre-Elimination Round B. Rest of the teams who couldn't make it to Elimination Round can compete in Pre-Elimination Round B to make their way to the Elimination Round.

Joining me and arjunarul (Arjun Arul) on the problem setting panel, we have kingofnumbers (Hasan Jaddouh) as tester. The rest of the panel members include:

• Russian Translator: CherryTree (Sergey Kulik)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese translators: VNOI team
• Editorialist: sidhant (Siddhant Bansal)

Given below are the details of the contest.

We hope you will enjoy the problems and we welcome your feedback in the comments below.

Start Time: Wednesday, 31st May, 2017 at 21:00 HRS. (Indian Standard Time +5:30 GMT) Check your timezone here.

Duration:: 24 hrs

Contest link: https://www.codechef.com/SNCKPB17

Accepted Languages: https://www.codechef.com/wiki/list-compilers

Note: Teams in the top 1000 ranks will move to the Elimination Round. This is the final opportunity for teams to qualify for Elimination Round.

Good Luck!

Hello CodeForces Community,

SnackDown 2017 Qualifiers has seen participation from over 21K teams across the globe. Of which 12859 teams have been advanced to Pre-Elimination Rounds. Complete list of the selected teams can be found here: https://www.codechef.com/rankings/SNCKQL17.

Problems of Pre-Elimination Round A are set by PraveenDhinwa (Praveen Dhinwa) and arjunarul (Arjun Arul) tested by kingofnumbers (Hasan Jaddouh). The rest of the panel members include:

• Russian Translator: CherryTree (Sergey Kulik)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese translators: VNOI team

Upon concerns raised by the community regarding the clash of timings between the May LunchTime and SnackDown Pre-Elimination Round A, the latter has been postponed by 2 hrs. The SnackDown Pre-Elimination Round A will now start at 27th May 11:00 PM IST (check your timezone here). We apologize for the inconvenience caused and wish you all the very best for both the contests!

We hope you will enjoy the problems and welcome your feedback in the comments below.

Start Time: Saturday, 27th May, 2017 at 23:00 HRS. (Indian Standard Time +5:30 GMT) Check your timezone here.

Duration:: 24 hrs

Contest link: https://www.codechef.com/SNCKPA17

Accepted Languages: https://www.codechef.com/wiki/list-compilers

Note: Teams in the top 1000 ranks move to the Elimination Round. Rest of the teams who could not advance to the Elimination Round through the Pre-Elimination Round A, get another opportunity to go to the Elimination round by taking part in the Pre-Elimination Round B.

Happy programming !!

Hello CodeForces Community,

I would like to invite you all for the SnackDown 2017 Online Qualifier starting today (i.e 20th May) at 17:00 hrs, IST. Hosted by CodeChef, SnackDown is one of the biggest onsite programming events around the globe. The contest has seen participation from some of the finest programmers from all over the globe and this year it promises to get even better with no restriction on team formation. Yes, for SnackDown 2017 you can form teams with anyone from anywhere in the world. So, if you have not yet formed and registered your teams, I suggest you do it now.

Some key highlights of SnackDown 2017 include:

• Cash prizes worth $20.5K and Goodies worth $15K
• An all-expense paid trip to SnackDown Finals in Mumbai, India (for all the eligible finalists)
• 57 teams from across the globe to be invited to the onsite finale in Mumbai, India
• Special slots for school and women teams I am sure you will enjoy competing in all the rounds of the contest and eventually some of you will be on that plane to Mumbai. So, hurry up. The details of the 4 day qualifying are:

SnackDown 2017 Online Qualifier:

• Start Date: 20th May 2017, 17:00 Hrs IST
• End Date: 24th May 2017, 17:00 Hrs IST
• Duration: 4 days

Note: A team needs to solve one problem to advance to the next round during the Qualification Round. Complete schedule of the event can be found here: https://www.codechef.com/snackdown/2017/schedule

Problem Setting Panel:

• Problem Setter & Contest Admin: PraveenDhinwa (Praveen Dhinwa)
• Tester: kingofnumbers (Hasan Jaddouh)
• Editorialist : kingofnumbers (Hasan Jaddouh)
• Russian Translator : CherryTree (Sergey Kulik)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese Translator: VNOI Team

Hope to see you all on the rank list. Break a leg.

I am happy to announce the CodeChef SnackDown 2017 schedule. As you might know SnackDown is the largest onsite programming event held in India, with participation of teams from all over the globe. It is open for anyone with a knack of programming. Whether you are studying in school, or college, a working professional, or a self taught programming brilliance, you are absolutely eligible to take part and win prizes. You can compete in teams of two and most importantly there is no restriction on team formation in this year’s edition. One can team up with anyone across the Globe and compete!

For the SnackDown 2017 schedule head over to: https://codechef.com/snackdown/2017

For more details about the rule change and finalization of dates, please visit: https://blog.codechef.com/2017/03/12/snackdown-2017-is-here-and-this-time-it-is-truly-open/

We shall get back to you with further details soon!

Hello CodeForces Community,

Let me take this oppourtunity to invite you to CodeChef November LunchTime 2016 at https://www.codechef.com/LTIME42. For those who aren’t aware, LunchTime is an IOI Style contest wherein you can score based upon the number of test cases you pass in the problem..

Joining me on the problem setting panel are:
Contest Admin and Setter: PraveenDhinwa (Praveen Dhinwa)
Problem Tester: animeshf (Animesh Fatehpuria) and quite a help of kevinsogo(Kevin Charlest Atienza)
Editorialist: pkacprzak (Pawel Kacprzak)
Mandarin Translator: huzecong (Hu Zecong)
Vietnamese Translator: VNOI Team
Russian Translator: CherryTree (Sergey Kulik)

I hope you enjoy solving them. Please give me your feedback on the problem set in the comments below after the contest. You shall find the rest of the details about the contest below.

Time: 26th November 2016 (1930 hrs) to 26th November 2016 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your http://www.timeanddate.com/worldclock/fixedtime.html?msg=CodeChef%3A+November+Lunchtime+2016&iso=20161126T1930&p1=44&ah=3 .

Details: https://www.codechef.com/LTIME42

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, please [https://www.codechef.com/user/register] (register here) in order to participate.

Prizes: Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: https://www.codechef.com/laddu. (For those who have not yet got their previous winning, please send an email to [email protected])

Good Luck! Hope to see you participating!!

Hello CodeForces Community,

I would like to co-ordily invite you all to take part in the CodeChef August Lunchtime. It is an IOI Style contest which will last for 3 hrs.

The problems were set by CherryTree (Sergey Kulik) and tested by harshil (Shah Harshil Ketankumar), the rest of the panel members include:

• Editorialist: pkacprzak (Paweł Kacprzak)
• Russian Translator: CherryTree (Sergey Kulik)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese Translator: VNOI Team
• Contest Admin: PraveenDhinwa (Praveen Dhinwa)

I hope you will enjoy solving the problems. Please give me your feedback on the problem set in the comments below after the contest. You shall find the rest of the details about the contest below.

Time: 27th August 2016 (1930 hrs) to 27th August 2016 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Details: https://www.codechef.com/LTIME39

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, please register here in order to participate.

Prizes:

• Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: https://www.codechef.com/laddu. (For those who have not yet got their previous winning, please send an email to [email protected])

Good Luck! Hope to see you participating!!

Hello Codeforces Community!

I would like to co-ordially invite you to participate in the CodeChef July Long Challenge. As always, it starts on the 1st Friday of the month and will last for 10 days, giving you two weekends to have a go at the problems.

• Joining me on the problem setting panel are: Antoniuk (Vasya Antoniuk), EG0R Egor Bobyk, Omelianenko Andrii Omelianenko, PraveenDhinwa (Praveen Dhinwa), Berezin Dmytro Berezin, CherryTree Sergey Kulik, mgch Misha Chorniy, kevinsogo Kevin Charles Atienza, Le Mike
• Language Verifier & Contest Admin: PraveenDhinwa (Praveen Dhinwa)
• Testers: mugurelionut (Mugurel Ionut Andreica)
• Russian Translator : Antoniuk (Vasya Antoniuk)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese Translator: VNOI Team

Please feel free to provide the feedback about the problems in the comments.

Start Time: 1st July 2016 (1500 hrs) to 11th July 2016 (1500 hrs). (Indian Standard Time — +5:30 GMT) — Check your time zone.

Details: https://www.codechef.com/JULY16

Registration: You need to have a CodeChef handle to participate. For all those, who are interested and don’t have a CodeChef user handle are requested to register in order to participate.

Prizes:

For Global participants:

1st prize: $400 2nd prize: $300

Hello CodeForces Community!

I would like to invite you to the Replay Contest of CodeChef SnackDown 2016 Pre-Elimination Round B which begins in few hours i.e at 9 PM IST, 13th June, just after the main contest.

The problems have been set and tested by kevinsogo (Kevin Charles Atienza), Antoniuk (Vasya Antoniuk), CherryTree (Sergey Kulik) and the translations are written by huzecong (Hu Zecong), Antoniuk (Vasya Antoniuk), VNOI Team, CherryTree (Sergey Kulik), with PraveenDhinwa (Praveen Dhinwa) as contest admin.

Registration: The contest is open for all and it will be a team based contest with a maximum of up to 2 members in a team. One need to have a CodeChef account and register as a team here to take part in the contest.

Contest link: https://www.codechef.com/SNPB16RP

I am sure it promises to deliver an interesting problem set, hope you enjoy solving the problems. Please feel free to give your feedback about the problems in comments below.

See you all at the contest.

Regards,
Praveen Dhinwa

Hi All !!

Congratulations to all those who have cleared the SnackDown 2016 Pre-Elimination Round A and advanced to the SnackDown Elimination. For those who couldn’t compete/clear Pre-Elimination Round A, here is your chance to make it to the Elimination Round through Pre-Elimination Round B. The ranking criteria for this contest will be score based. And, top 1000 teams (other than top 1000, the teams solving problems same number of problems equal to 1000th team) will advance to the elimination round.

The CodeChef SnackDown 2016 Pre-Elimination Round B begins tomorrow i.e at 9 PM IST, 12th June.

Note: Those who have already made it to the SnackDown Elimination will not be allowed to take part in this contest.

The problems have been set and tested by kevinsogo (Kevin Charles Atienza), Antoniuk (Vasya Antoniuk), CherryTree (Sergey Kulik) and the translations are written by huzecong (Hu Zecong), Antoniuk (Vasya Antoniuk), VNOI Team, CherryTree (Sergey Kulik), with PraveenDhinwa (Praveen Dhinwa) as contest admin. I hope you will enjoy solving the problems. Please feel free to give your feedback about the problems in comments below.

• Furthermore, this year, CodeChef will be inviting 52 team’s (top 25 global + top 25 Indian + all Girl team + Indian school team) for the onsite finals. Of these 52 teams, 32 teams (top 15 each Global & Indian + Girl + Indian school team) will get an all expense paid trip to India, while the remaining 20 teams will be provided with accommodation and local travel in India. However, if any of these 20 teams win the competition, their travel fair will be reimbursed as well. It’s a win-win situation.

Along with the cash prizes for Global Winners, there are special prizes for Best School Team, Best Girls team and Best Indian Team (the total cash prizes are worth $22,500).

• The winning team shall win a whooping cash prize of $10,000.
• Also, taking into consideration the previous discussions regarding the timing of online elimination round of the contest, the organizers have decided to reschedule the round.

The new timings for the SnackDown 2016 Elimination Round are:

• Time: 19th June 2016, 7:30 pm to 12:30 am 20th June 2016 IST.

In order to accommodate the new timings, they have also rescheduled the June Cook-Off 2016. And the new timings for the June Cook-Off are:

Date & Time: 26th June 2016, 21:30 Hrs IST to 00:00 Hrs IST

I hope you like the new timings and that will enjoy the contest till the very end. That will be all from my side for now. See you all at the contest.

Regards,
Praveen Dhinwa

Hello CodeForces Community,

I would like you to invite for March LunchTime. The contest takes place at https://www.codechef.com/LTIME34. I am sure this will serve as a good practice for all those aiming for IOI 2016, we have adhered to the syllabus IOI and made the problems accordingly.

Time: 26th March 2016 (1930 hrs) to 26th March 2016 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone

Details: https://www.codechef.com/LTIME34

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.

• Problem Setter & Russian Translator: CherryTree (Sergey Kulik)
• Editorialist: pushkarmishra (Pushkar Mishra)
• Problem Tester: totsamyzed (Vlad Mosko)
• Contest Admin: PraveenDhinwa (Praveen Dhinwa) and pushkarmishra (Pushkar Mishra)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese Translator: VNOI Team

Special Prizes for March LunchTime 2016:

• Top 10 school students each from Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: https://www.codechef.com/laddu. (For those who have not yet got their previous winning, please send an email to [email protected]).

Not just that March Lunchtime 2016 will be waiting with 2X more laddus up for grabs. Yes, in true spirit of Holi and CodeChef’s anniversary, they are awarding 2X more laddus to the winners. Hope this gives you 2X more reasons to participate :D Rest, it promises to deliver on an interesting set of algorithmic problems with something for all. Please feel free to give your feedback on the problem set.

Good Luck! Hope to see you participating!!

Please note that the contest starts in 40 minutes

If some of you had missed the mirror contest of ACM ICPC Chennai onsite regional, 2015, you still have a chance to participate in the replay contest of it. The replay will be on next Sunday (14th Feb) from 7 PM to 12PM IST. You can view start time in other timezones here.

Contest link is https://www.codechef.com/CHN15MRP.

The contest will be a team contest. A team can consist of at max 3 members. You can register for the contest here.

The problem set of the contest contains some really nice problems. It will be a great experience for you to try to get the feel of ACM ICPC experience, if your team was not selected in the regionals. Even if your team was selected, you can still try the problems that you did not solve ;)

After the end of the contest, you will be served awesome detailed editorials by Kevin Charles Atienza (kevinsogo).

Problem panel for this contest consists of following persons.

Problem setters:
Ajay Verma (djdolls)
Animesh Fatehpuria​ (animeshf)
Arjun Arul​ (arjunarul)
Malvika Raj Joshi ([user:a06]​)
Praveen Dhinwa​ (PraveenDhinwa)
Surya Kiran (adurysk)​.

Problem testers:
Jingbo Shang (shangjingbo)
Kevin Charles Atienza (kevinsogo)

Editorialist :
Kevin Charles Atienza (kevinsogo)

Special Mention
We had a long discussion of problem difficulties and suggestions about quality of problems with Utkarsh Lath​ (utkarshl).

Happy programming to all of you !!

Please mark the date on your calendar. You can set reminder for the contest on the codechef site too.

Hi All,

There would be a mirror contest of ACM ICPC Chennai onsite regionals on codechef on 23rd Saturday. It will start from 11 AM IST. It will be a 5 hours team contest.

Event timings for various time zones can be found here

We will let you know about the entire panel and problem setters after the contest.

It is a team contest. Contest link will be https://www.codechef.com/CHN15MOS/.

You can register at https://www.codechef.com/teams/register/CHN15MOS

Happy programming !! We hope that you really enjoy the set !!

Contest has been delayed by half hour due to syncing with onsite contest. Now it will start at 11:30 AM

Hello Codeforces Community!

CodeChef invites you to participate in CodeChef September Long Challenge at http://www.codechef.com/SEPT15.As always, the long contests will start on first Friday of every month and last for 10 days. This ensures that two weekends are covered.

Time: 4th September 2015 (1500 hrs) to 14th September 2015 (1500 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Details: https://www.codechef.com/SEPT15

Registration: Just need to have a CodeChef handle to participate. For all those, who are interested, are requested to register in order to participate.

• Problem Setters : minimario (Alex Gu) M0sTik (Andrii Mostovyi) TonySnark (Evgeni Artemov), Xellos (Jakub Safin), darkshadows (Lalit Kundu), mgch (Misha Chorniy), KaiZeR (Kirill Shchetinin), and Rebryk (Yuriy Rebryk)
• Editorialist: suh_ash2008 (Suhash Venkatesh) and pushkarmishra (Pushkar Mishra)
• Problem Tester: kevinsogo (Kevin Atenzia)
• Contest Admin: PraveenDhinwa (Praveen Dhinwa)
• Russian Translator : CherryTree (Sergey Kulik)
• Mandarin Translator: gediiiiiii (Gedi Zheng)
• Vietnamese Translator: VNOI Team
• Language Verifier: RahulArora Rahul Arora

Note: Starting from September Challenge 2015, CodeChef will be providing problem statements translations in Vietnamese.

Prizes:

For Indians:

1st prize: INR 12000
2nd prize: INR 8000

For Rest of the world:

1st prize: $400
2nd prize: $300

In addition to the above prizes. Top 10 global, Top 20 Indian, Top 5 school (Indian), Top 5 school (Global), Top 3 challenge problem solvers Indian and Global (apart from the winners) get cool CodeChef goodies, and top 5 girl coders will be provided with goodies, given that they are among top 100 in the final ranklist (this will be irrespective of the region).

It promises to deliver on an interesting set of algorithmic problems with something for all. Good Luck! Hope to see you participating!!

Hi All,

Final rankings of the contest.

Overall top 5 in onsite ranking

1. ancalagon from IIT Bombay consisting of Balajiganapathi and Deepa Panwar
2. smack_down from Tower Research Captial consisting of Smit Hinsu (Smit) and Siddharth Bora (SiddharthBora)
3. logicmonks_ from Google consisting of Akashdeep Nain (akashdeep) and Nishant Redkar.
4. sandy_team from IIT Bombay consisting of Sai Sandeep (harrypotter192).
5. believe_iiith from IIIT Hyderabad consisting of Pulkit Goel (pulkitg10) and Vivek Hamirwasia (viv001)

Overall top 5 in final online ranking.

1. aapppppppiii from Tsinghua University having Apia Du and Yinzhan Xu (xyz111)
2. rake_compress from ITMO consisting of Gennady Korotkevich (tourist) and Borys Minaiev (qwerty787788)
3. two_captains from Yandex consisting of Mikhail Tikhomirov (Endagorion) and Alexander Mashrabov (map)
4. sjtu_01 from Shanghai Jiao Tong University consisting of Haobin Ni (TankEngineer) and Yanpei Liu (BaconLi)
5. ench_mango from National Taiwan University consisting of Peter Shih (peter50216) and Kelvin Yang (kelvin).

Congratulations too all of you :) You really deserve it !!!

Overall onsite ranking can be seen here.
Overall finals ranking can be seen here.
Also, mirror ranks can be seen here.

You can check codechef blog to check interviews of many top teams in which they have answered quite interesting and important questions about their preparations, motivation, mistakes etc. I think it will be quite interesting to read that.

Live streaming of the contest can be seen here

6:00 PM Contest has added. I hope that you enjoyed the problems and the contest too :) We will update the ranking in a few hours. Thank you all for joining :) Mirror contest is still running, please feel free to participate in it and enjoy the problems prepared by Chef :)

5:53 PM There is a flurry of submissions going from all the teams :) We will see who gets which problems and who becomes the overall winner and onsite winner of the contest?

5:47PM A team playing solitaire during the contest :P

5:42PM Few pics from the arena

5:00 PM Ranking before freezing time

1. rake_compress from ITMO
2. aapppppppiii from Tsinghua University
3. two_captains from Yandex
4. sjtu_01 from Shanghai Jiao Tong University
5. sequoia from Moscow Institute of Physics and Technology
6. dreamoon_shik from National Taiwan University
7. kut_team1_sd from Kim Chaek University

Onsite rankings

1. ancalagon from IIT Bombay
2. smack_down from Tower Research
3. logicmonks_ from Google
4. sandy_team from IIT Bombay
5. believe_iiith from IIIT Hyderabad
6. naive_coders from IIT Kanpur
7. scc_snack15 from BITS Pilani

4:58 PM Team rake_compress consisting of tourist and qwerty787788 is on top of the ranking board just before the freezing time. Will team aapppppppiii from Tsinghua be able to beat them during the freezing time?

4:48 PM Problem setters with their problem names

Sergey Kulik(CherryTree) -> SHUFFLE2, GUARDS, WMIS
Kevin Charles Atienza(kevinsogo -> RAMSINSP, FUZZYADD, CHEFNKCH
Utkarsh Lath (utkarshl -> ANDMAT, BUGATACK
Istvan Nagy(iscsi) -> TENNIS
Praveen Dhinwa(PraveenDhinwa) -> NICENESS and TIMETRAV

4:41 PM Team rake_compress consisting of tourist and qwerty787788 has too solved the 9th problem and is retaining their 2nd position. There are 15 minutes before the freezing of the round. Let us see whether they will be able to fetch a win like they have done in many other contests or whether this time aapppppppiii will defeat them?

4:36 PM Team faceless_man from IIT Kanpur consisting of Sahil Grover and Atanu Chakraborty sent following postcard message for other teams.

If content is unreadble for you, then here it is "Iterate from 26 to 2 because 1 is me :)"

4:24 PM We will be freezing the contest for last hour. Let us see what suspense unfolds in the last hour. Will rake_compress beat aapppppppiii ? Will there be any changes in top 3 of the onsite ranklist ? How many more problems will be solved by onsite participants etc .

4:22 PM You can see interviews of Team aapppppppiii from Tsinghua University having Apia Du and xyz111 here. Their interview is quite interesting :)

4:18PM 9 problems have been solved by at least one problem. Two more problems are yet to go.

4:14 PM Team aapppppppiii consists of Apia Du and xyz111 are on fire. They are having first position in almost all the contest. They have solved total whopping 9 problems just having 2 more to go in 1 hour and 45 minutes :)

4:09 PM Pic Request by NeverSayNever

Team logicmonks from Google consisting of Akashdeep Nain (akashdeep) and Nishant.

4:08 PM Team rake_compress consisting of tourist and qwerty787788 has too solved the 8th problem. It is getting quite interesting. First and second team positions have only 7 minutes penalty difference. :)

4:05 PM Team aapppppppiii consists of Apia Du and xyz111 submitted their 8th problem just now and gain a solid lead of 1 problem.

4:00 PM Team bandb from IIITH is at currently 9th position. Their team has darkshadows and Nikhil.

3:58 PM Top 5 teams from the India are

1. ancalagon from IIT Bombay
2. smack_down from Tower Research
3. logicmonks_ from Google
4. sandy_team from IIT Bombay
5. believe_iiith from IIITH

3:55 PM Top 5 teams have solved 7 problems each. There are total 3 problems which are yet to be solved by anybody. Let's see in the next upcoming hours :)

3:52 PM

Team scc_snack15 from BITS Pilani consisting of Ankul Sareen (akulsareen) and Pranet Verma( pranet)

3:48 PM From onsite contest point of view, there are not much changes in top 5-6 rankings.

3:44 PM Team from my own institute IIT Kanpur, naive_coders having triveni and sshekh currently at position 6th position.

3:39 PM Currently, teams rake_compress and Havka-papstvo are trying to solve problem RAMSINSP. Let's see what happens in few hours !! If rake_compress solves this problem, then they can be at top position.

3:33 PM Egor and pashka's team Havka-papstvo has solved 5 problems and currently at 10th position.

3:23 PM Total 8 problems have been solved. kut_team1_sd from DPRK is the only team to solve BUGATACK problem. Their team consists of kutengine and SuRyong Kim. They have solved total 5 problems. It would be quite nice too see how they solve problems in next few hours.

3:15 PM Now team aapppppppiii and rake_compress are really close with 1st and 2nd positions respectively. One has penalty of 7:25 whereas other has 7:28. Just 3 minutes difference. Both have solved same problems. So, let us see which one is able to find next problem to solve fast :)

3:10 PM There has been a flurry of submissions now in onsite round, top 3 teams have solved 4 problems. Their order has not been changed yet.

3:05 PM
Here is the team from DPS Dwarka, its members (Rajat De and Aditya Popali) has been participants of IOITC camp (training camp for IOI in India).

.

3:00 PM Summary of the contest till now
Almost all onsite teams (24 out of 25 teams) have solved at least one problem.
Total 7 problems have been solved.
Top Indian team ancalagon has solved 4 problems whereas in overall ranking team aapppppppiii has solved whopping total 7 problems which is leading the ranking almost during the entire duration of contest.

2:51 PM Team aapppppppiii consists of Apia Du and xyz111. It will be really interesting to see these guys participating in upcoming ICPC world finals. 2nd, 3rd and 4th ranked teams have famous participants who have achieved a big success in programming contests :)

2:45PM Team rake_compress consisting of tourist and qwerty787788 from ITMO has solved the problem SHUFFLE2 after 2 wrong attempts. They are still at second position.

Team aapppppppiii from Tsinghua is still leading the contest. Next few upcoming hours will be worth watching :)

Teams from NTU are currently at 3rd and 4th positions.

Team ench_mango is at 3rd position. It consists of peter50216 and kelvin.

Team dreamoon_shik is at 4th position. It consists of dreamoon_love_AA and Shik as their name suggests.

2:40 PM Team sandy_team consisting of Sai Sandeep from IIT Bombay.

2:38 PM Team rake_compress consisting of tourist and qwerty787788 from ITMO is currently struggling in the problem SHUFFLE2.

2:36 PM Youngest team consisting of a single team member Mriganka has solved one problem.

2:30 PM Team believe_iiith from IITH consisting of pulkitg10 and viv001 currently at third position in onsite contest

2:28 PM In online mirror, jenabkhan is leading with solving two problems. Participation is slightly less in the mirror round. Hope to see more participation in upcoming time.

2:26PM
Total 21 teams have solved at least problem in onsite contest. There are 4 more teams to solve at least one problem.

2:15 PM: Team smack_down ranked 2 in onsite contest.

Smit Hinsu and Siddharth Bora from Tower Research Captial

2:13 PM: Team ancalagon leading the onsite ranking.

Balajiganapathi and Deepa Panwar from IIT Bombay

2:11 PM: aapppppppiii and rake_compress are having a pretty close competition with each other. rake_compress is just having 1 extra penalty points. There are two problems which are solved by only one of the teams. So, we hope to see ranking changes in next few hours or so.

2:08 PM: Currently total 6 problems have been solved. There are still 5 problems to be solved.

2:04 PM: Currently the ranking has not changed much. Team from google, logicmonks_ has come to third place replacing believe_iiith which has been an ICPC world finals team from India. Team logicmonks_ consists of Akashdeep Nain and Nishant Redkar.

2:00 PM: The finals mirror contest has been started. Let us see how it unfolds :)

1:58 PM, Team ancalagon is leading the onsite contest from the beginning of the contest. Total 14 teams has solved at least some problem in first hour. So, there are still 11 teams remaining to solve anything.

We will post images of participants here in few minutes :)

1:55 PM Please note that the finals mirror will start in 5 minutes. You have some information about number of solved problems with you already :) Bring it on !! Happy programming to all.

1:47 PM: Team aapppppppiii from Tsinghua is currently leading the scoreboard. rake_compress is currently ranked 2. It would be interesting to see what folds in few upcoming hours.

1:44 PM: Current online finals rankings

1. rake_compress consisting of tourist and qwerty787788 from ITMO (Saint Petersburg National Research University of Information Technologies, Mechanics and Optics).

2. two_captains from Yandex consisting of Mikhail Tikhomirov (Endagorion) and Alexander Mashrabov (map)

3. sequoia consisting of Alexander Ostanin (Kostroma) and Alexey Dmitriev (riadwaw) from Moscow Institute of Physics and Technology

4. dreamoon_shik consisting of dreamoon_love_AA from National Taiwan University.

1:40 PM: Currently total 4 problems have been solved by at least one team ANDMAT, WMIS, TENNIS, NICENESS.

1:39 PM: Team sandy_team is now on top of onsite contest. The team consists of Sai Sandeep from IIT Bombay.

1:37 PM: team ancalagon is on fire. It has solved 2 problems to currently lead the onsite finals.

1:30 PM: It's been half an hour after the contest has started.
Currently, team rake_compress consisting of tourist and qwerty787788 is leading with solving three problems.
From the onsite contest, team ancalagon consisting of Balajiganapathi and Deepa Panwar from IIT Bombay is leading with solving one problem.

It seems that nobody has posted about the round till now, so I thought of posting about it.

It will start on Sunday from 17:30 IST, 15:00 MSK, 12:00 PM UTC. Please check your timezone here

More details about the contest can be found here. This round is also a regional event which will be held in ITMO University. Maximum 40 people will advance to next round.

Best of luck to all !!!

Let's discuss problems here after the contest !!