Upd. TCO Marathon Leaderboard.
Upd.2. Due to the issues with the contest not showing up in some listings of active contests, the round is extended by 24 hours, till June 14th.
This year the online part of the Marathon competition consists of 4 main rounds, each running for a week. The winner of each main round advances to the finals, and so do 8 participants who accumulated the most points across all main and lightning rounds. 150 competitors who accumulate the most points get t-shirts; given that each round awards points to top 50 places, it's quite possible that the t-shirt condition will transform into "top 50 in each round get t-shirts".
TCO18 Warsaw regional event will take place on May 12th. It will include an Algorithm competition round which will allow the top 10 scorers to advance to the Online Wildcard Round. You can read more about Algorithm rules here.
A lightning Marathon match MapRecoloring started on May 4th and will run for 3 days. It will be the first of TCO18 Marathon rounds, awarding TCO points for top 50 participants, as described here. It will also feature prizes for top 3 online participants and top 3 participants present at the regional event. I am the writer of the Marathon problem :-)
JAPE riddle generator is a program which can produce question-answer puns. This problem has been inspired by one of the witticisms produced by it:
What do you call a quirky quantifier? An odd number.
All you had to do was to check whether the given "quantifier" was "quirky".
This problem was inspired by the awesome book "Surely You're Joking, Mr. Feynman!" In one of his stories Feynman asks a librarian to fetch him a map of a cat, having a zoological chart in mind. Of course, such a serious interpretation was unsuitable for my purposes :-)
This was a perfectly straightforward problem: just pet the cat!
The contest is over; I hope you've enjoyed it :-) Editorial is here.
The 6th April Fools Day Contest will take place on Sunday April 1st. This is a joke competition in which solving the problem is often easier than figuring out what the actual task is.
This year I tried to make the problems less puzzling and more versatile. For example, almost all problems have a statement! And you won't need OEIS this time :-)
In this round you'll be given 7 weird problems and 2 hours to solve them. The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated. You can submit solutions in any language allowed by Codeforces. To get an idea of what the contest will look like, you can check out the contests of the past years: 2012, 2013, 2014, 2016, 2017.
As usual, to enjoy competing in this round you'll need a sense of humor compatible with mine! Good luck, and have fun!
Upd: Topcoder has announced prizes for MM 100 participants:
The most straightforward solution is to generate all possible logins (by trying all non-empty prefixes of first and last names and combining them) and find the alphabetically earliest of them.
To get a faster solution, several observations are required. First, in the alphabetically earliest login the prefix of the last name is always one letter long; whatever login is generated using two or more letter of the last name, can be shortened further by removing extra letter to get an alphabetically earlier login.
Second, the prefix of the first name should not contain any letter greater than or equal to the first letter of the last name, other than the first letter.
Thus, a better solution is: iterate over letter of the first name, starting with the second one.
Codeforces Round #455 for Div 2 competitors will be held on December 27 at 19:35 MSK. As usual, Div 1 competitors can join out of competition.
The round will be rated.
This round is based on tasks for summer contest for interns algO(1). If you have seen the problems from that contest before, please don't participate in the round. The problems were prepared by Maxim Kalinin (slycelote), Alexander Milanin (Milanin), Ibragim Ismailov (ibra) and me (Nickolas).
The competitors will be given six problems and two hours to solve them. The scoring distribution will be 500-1000-1500-1750-2000-2500.
We hope you'll like the problems. Good luck!
UPD: The contest is over. Editorial can be found here.
Congratulations to winners!
Several Marathon matches were added to Topcoder event calendar:
The third round of TCO17 Marathon Competition PoisonedWine started yesterday. It will run for two weeks, and top 30 competitors will get points which then will be converted to t-shirts and trips to the finals (here are the rules). This time the problem was written by timmac, I'm just the tester.
On Friday Topcoder announcement date and location for TCO17 finals — October 20-24, Buffalo, NY.
And today we launched a themed Marathon match WaterfallFishing — rated but without any TCO points. It will run for one week (till May 29), and will have this week's Data Science Weekly Challenge associated with it.
The second round of TCO17 Marathon Competition AbstractWars started today. It will run for two weeks, and top 30 competitors will get points which then will be converted to t-shirts and trips to the finals (here are the rules). Besides, this round will have two Data Science Weekly Challenges associated with it (which I still have to come up with). I am the writer, enjoy! :-)
On Saturday, May 7th Topcoder Open returns to Saint-Petersburg, Russia! Event program includes:
If you want to participate, register.
Upd. List of registrants
Incredibly, 34 people managed to solve all problems! 1032 participants solved at least one problem, and it wasn't always A :-)
Traditionally the first problem of April Fools Day contest asks to recognize a sequence of integers by problem title and (this time) a single data point. OEIS search for just the given number isn't going to give a result — or rather is going to give too many to be useful. However, if you look for the problem title, the first result for "numbers joke" query will give you https://oeis.org/A006753 "Smith (or joke) numbers", which has 27 as its 3rd element.
This problem is a variation on a kid's riddle in which you have to count closed loops in digits of the number — one in 4, 6, 9 and 0 and two in 8.
The contest is over; I hope you've enjoyed it :-) Editorial is here.
The fifth April Fools Day Contest will take place on Friday March 31st. This is a joke competition in which solving the problem is often easier than figuring out what the actual task is. Thanks to kit1980 and Codeforces team for their help in preparing problems!
In this round you'll be given 7 weird problems and 2 hours to solve them. The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated. You can submit solutions in any language allowed by Codeforces. To get an idea of what the contest will look like, you can check out the contests of the past years: 2012, 2013, 2014, 2016.
Be warned, to enjoy competing in this round you'll need a sense of humor compatible with mine! Good luck, and have fun!
Marathon Match 91 WanderingTheCity will start on October 19/20 and run for two weeks. The match is very unusual — there is no real-life problem, and there are no prizes or trips to the finals :-) I am the writer.
A quick update on the status of e-maxx translation project.
First, I'm excited to announce that I've joined e-maxx in English team as an admin! From practical point of view this means that I can review and accept pull requests and help with the issues arising during the contribution process. Feel free to contact me if you have questions. And if I encounter anything outside of my expertise, I can always ping RodionGork directly :-)
Second, October is a particularly good month for contributions to e-maxx translation, as well as for open source contributions in general. Hacktoberfest is back this year, and they are giving away t-shirts to anyone who makes 4 pull requests to any GitHub-hosted projects between October 1st and 31st.
We don't have an explicit list of issues to work on, but there are two basic kinds of contribution we're looking for:
So if you have at any point considered contributing to e-maxx translation, now is the time to do it :-)