Hello CodeForces Community!

CodeChef’s 44th edition of LunchTime programming contest — the January LunchTime 2017 coming your way with 4 savory problems to munch on. Aimed at School students, the LunchTime contest promises some fun programming action to all. So, in school or not, it’s time to bring out the programming wizard in you and join in the 3 hour contest.

So, go ahead, enjoy the start of the weekend and have a great week ahead!

We have the following on the problem setting panel:

• Problem Setter and Russian Translator: CherryTree (Sergey Kulik)
• Problem Tester: Errichto (Kamil Debowski)
• Editorialist: pkacprzak (Pawel Kacprzak)
• Mandarin Translator: huzecong (Hu Zecong)
• Vietnamese Translator: VNOI Team
• Contest Admin PraveenDhinwa (Praveen Dhinwa)

Hope you will enjoy solving them. Please give your feedbacks on the problem set in the comments below after the contest.

Please find the rest of the details about the contest below.

Time: 28th January 2017 (1930 hrs) to 28th January 2017 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Details: https://www.codechef.com/LTIME44

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.

Prizes: 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 winners@codechef.com).

Good Luck! Hope to see you participating!!

Congratulations to all those who have cleared the SnackDown Pre-Elimination Rounds and advanced to the SnackDown Elimination! An intense competition is about to begin where only the top 52 teams will move on to the SnackDown Onsite Finale.

The Elimination Round will have an ACM ICPC style rank list. As mentioned above, 52 teams (Top 25 Global + Top 25 Indian + Best Girl’s team Global + Indian School team) will be invited to the onsite finals. While the top 32 teams (15 each Global & Indian + Best Girl’s team + Best Indian School team) will get an all expense paid trip to Mumbai, India, 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.

Also, top 300 teams will be getting SnackDown 2016 merchandise from CodeChef.

The CodeChef SnackDown 2016 Elimination Round begins at 19:30 HRS IST, 19th June.

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

Hope to see an exciting competition in the SnackDown Elimination!

The 20-th edition of Week of Code https://www.hackerrank.com/w20 starts soon: 23 May 16:00 UTC.

Monday to Friday, every day one challenge will go live, easy to hard. The maximal score decreases by 10% at the end of every 24 hours. Your submissions will run on hidden test cases at the end of every 24 hours.

The time of each challenge will be counted since it's open. It allows you to start late.

The contest is prepared by CherryTree and tested by shef_2318

The contest is rated and top 10 get T-shirts.

GL & HF

Hello Codeforces community!

I am glad to announce that HackerRank 101 Hack 30th edition will be held on 21th October 2015 at 16:30 UTC. You can sign up for the contest here. Though what's priceless is solving interesting problems and the thrill of competition, prizes make the competition fierce. Top 10 performers will get a HackerRank T-shirt.

Problems have been set by me and tested by wanbo. The contest will consist of 5 problems with variable scoring distribution. We have tried our best to prepare a nice problem set. Hopefully everyone will enjoy. Also, you'll be able to enjoy the detailed editorials written by the setter after the contest.

Good luck and have fun!

Hello Codeforces Community!

CodeChef invites you to participate in CodeChef October Long Challenge at http://www.codechef.com/OCT15 . 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: 2nd October 2015 (1500 hrs) to 12th October 2015 (1500 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Details: https://www.codechef.com/OCT15

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 : abhra73 (Abhra Dasgupta) kingofnumbers (Hasan Jaddouh) TonySnark (Evgeni Artemov), darkshadows (Lalit Kundu), mgch (Misha Chorniy), KaiZeR (Kirill Shchetinin),aangairbender Eugene Kazmin.
• Editorialist & Tester: CherryTree (Sergey Kulik)
• Contest Admin: PraveenDhinwa (Praveen Dhinwa)
• Russian Translator : CherryTree (Sergey Kulik)
• Mandarin Translator: gediiiiiii (Gedi Zheng)
• Vietnamese Translator: VNOI Team
• Language Verifier: RahulArora Rahul Arora

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!!

CodeChef invites you to participate in the CodeChef SnackDown Round 1B at http://www.codechef.com/SNCK2015.

Time: 30th May 2015 (0630 hrs) to 30th May 2015 (0830 hrs). (Indian Standard Time — +5:30 GMT) — Check out the local time in your City/Time Zone here.

Details: http://www.codechef.com/SNCK2015

Registration: Just need to have a CodeChef user id to participate.

New users please register here

Also, it is a team contest, so you need to register your teams first to take part in the contest. To register your team, register/login through CodeChef and go to: http://snackdown.codechef.com/register

- Problem Setters : abhra73 (Abhra Dasgupta) and Sergey Kulik
- Editorialist: kevinsogo (Kevin Atenzia)
- Problem Tester: kevinsogo (Kevin Atenzia) and iscsi (Istvan Nagy))
- Contest Admin: PraveenDhinwa (Praveen Dhinwa)
- Russian Translator : [user:Cherrytree]Sergey Kulik
- Mandarin Translator: MinakoKojima (Minako Kojima)

It promises to deliver on an interesting set of algorithmic problems with something for all.
The contest is open for all and those, who are interested, are requested to have a CodeChef userid, in order to participate.

Note: Participants who have qualified for elimination round are not allowed to take part in the Round 1B and the registrations will close one hour before the contest.

CodeChef invites you to participate in the November Lunchtime 2014 at http://www.codechef.com/LTIME18. This is an IOI style contest. This means that the problems will be partially graded. You will get score for passing certain test data.

Time: 30th November 2014, 1100 hrs to 1400 hrs. (Indian Standard Time — +5:30 GMT) — Check your timezone.

Details: http://www.codechef.com/LTIME18/

Registration: Just need to have a CodeChef user id to participate. New users please register here

- Problem Setter, Editorialist & Russian Translator : Sergey Kulik
- Problem Tester: Mahbubul Hasan
- Mandarin Translator: Gedi Zheng & Minako Kojima

It promises to deliver on an interesting set of algorithmic problems with something for all.
The contest is open for all and those, who are interested, are requested to have a CodeChef User ID, in order to participate.

Уверен, что я не один такой и что вопрос актуален.

Каждый из сообщества иногда выигрывает футболки на контестах, и конечно, каждый хочет получить свой приз.

Но уже где-то полтора года как, по приходу футболки в аэропорт присылается оповещение с тем, что ее надо забрать собственноручно, в аэропорту.

Беларусь — небольшая страна, но из некоторых городов дорога до аэропорта займет около девяти часов. Из столицы — часа два, но это все равно много. И забирая футболку надо заплатить, как правило 50-200 долларов — за футболку это много.

Поэтому, я уже привык просто игнорировать оповещения такого рода.

Получилось ли у кого-нибудь из Беларуси обойти это странное правило? Что надо сделать для того, чтобы футболки снова приходили к нам домой?

...Is here. It is always nice to hear other's approaches as well.

CodeChef invites you to participate in the June Lunchtime 2014 at http://www.codechef.com/LTIME13. This is an IOI style contest. This means that the problems will be partially graded. You will get score for passing certain test data.

Time: 29th June 2014, 1100 hrs to 1400 hrs. (Indian Standard Time — +5:30 GMT) — Check your timezone

Details: http://www.codechef.com/LTIME13/

Registration: Just need to have a CodeChef user id to participate. New users please register here

- Problem Setter, Editorialist, & Russian Translator : Sergey Kulik
- Problem Tester: Roman Furko
- Mandarin Translator: Gedi Zheng & Minako Kojima

It promises to deliver on an interesting set of algorithmic problems with something for all.
The contest is open for all and those, who are interested, are requested to have a CodeChef User ID, in order to participate.

CodeChef invites you to participate in the May Lunchtime 2014 at http://www.codechef.com/LTIME12. This is an IOI style contest. This means that the problems will be partially graded. You will get score for passing certain test data.

Time: 25th May 2014, 1100 hrs to 1400 hrs. (Indian Standard Time — +5:30 GMT) — Check your timezone.
Details: http://www.codechef.com/LTIME12/
Registration: Just need to have a CodeChef user id to participate. New users please register here

- Problem Setter, Editorialist, & Russian Translator : Sergey Kulik
- Problem Tester: Gedi Zheng
- Mandarin Translator: Gedi Zheng & Minako Kojima

It promises to deliver on an interesting set of algorithmic problems with something for all.
The contest is open for all and those, who are interested, are requested to have a CodeChef User ID, in order to participate.

Hi everybody!

A new kind of contest starts today at HackerRank. The contest is named "Daily Challenge".

Each day you get to solve a problem, the difficulty increases as the week progresses. You have a weekend to solve the final problem and there will be five problems in total.

This time, I'm a writer of this contest, so I invite everybody to participate. After the contest, there will be an editorial on HackerRank.

Now the contest has started and you have about 20 hours left to solve the first, the easiest problem.

I am the writer of this problem, I hope that somebody liked it ^^
I have described the solution here, but it seems to me that my solution is not the optimal one.
So it's very interesting to me to hear about your ideas and approaches to this problem, especially, about 80-100 point ones ^^

Вчера я написал небольшой пост о подготовке CodeChef LunchTime August. Несколько человек сказали, что он мог бы хорошо смотреться на Codeforces Так что я решил для интереса оставить ссылку на него здесь. Не судите строго :)

Hello!

I invite everybody to the August Lunch Time that will be held at CodeChef on this Sunday. You can check the starting time in your country here. This time, I am the writer of the contest.

You can find the problems of the two previous Lunch Times at codechef.com/LTIME01 and codechef.com/LTIME02.

In my point of view, this time the problems are significantly easier than the last two times, but nevertheless, I do hope that everybody will find something appropriate for him/her.

In case you don't know the rules here's the brief description: there are four problems with new-IOI-style grading (subtasks), so not only full solutions are considered. In case two contestants have got equal scores, the one whose last submission, which has improved his score was made first will be ranked higher. The scoreboard is visible during the whole competition. And there are separate rankings for the secondary school students.

Good luck and have fun ^_^

P.S. Feel free to discuss the problems here after the end of the contest.

UPD: The contest has started. You can find the problems here.

UPD: The contest has ended. Congrats to sy2006 — the only person who got 400 ^_^