Sphere Online Judge

Problem RKMINIMA is available

Wed, 01 Jan 2020 12:09:21 +0100

Problem RKMINIMA (36862. ) added by is now available in the classical problemset.

Read the problem text: RKMINIMA

Problem PERFSQNUM is available

Amitayush Thakur — Sun, 29 Dec 2019 20:37:16 +0100

Problem PERFSQNUM (36861. ) added by Amitayush Thakur is now available in the classical problemset.

Read the problem text: PERFSQNUM

Problem IBONEC is available

Manohar Singh — Sun, 29 Dec 2019 12:05:20 +0100

Problem IBONEC (36860. ) added by Manohar Singh is now available in the classical problemset.

Read the problem text: IBONEC

Problem GCOM is available

Fri, 20 Dec 2019 07:54:05 +0100

Problem GCOM (36797. ) added by is now available in the classical problemset.

Read the problem text: GCOM

Problem IDONTKNOW is available

Thu, 19 Dec 2019 12:55:57 +0100

Problem IDONTKNOW (36808. ) added by is now available in the basics problemset.

Read the problem text: IDONTKNOW

Problem COUNTDIO is available

Ania Piekarska Fan Club — Sat, 14 Dec 2019 10:54:53 +0100

Problem COUNTDIO (36789. ) added by Ania Piekarska Fan Club is now available in the classical problemset.

Read the problem text: COUNTDIO

Robert Lewoń — Wed, 20 Mar 2019 17:52:10 +0100

Are you passionate about coding?

Try your luck in a brain challenge and join ADB Brain Wars contest!

ADB Brain Wars is a contest organized for Polish programmers.

Check the details at: adb-brain-wars.com

Win great prizes and have a lot of fun!

The elimination round begins on the 25th of March

Visit the website: http://www.spoj.com/

Innopolis Open 2018

Robert Lewoń — Fri, 24 Nov 2017 10:36:04 +0100

Seven days left to register for the Innopolis Open - Olympiad in Informatics for high school students under 19 years old held by Innopolis University. The Olympiad has two stages: the online contest and the on-site competition.

Why participate?

It is a top-level contest - the problems on the Olympiad meet the level of the Russian Olympiad in Informatics. Contests are prepared under the guidance of the World Finals Champions of ACM ICPC.
Scholarship - winners of the second (on-site) stage will have an opportunity to be enrolled in Innopolis University without any admission tests.
Prizes – participants with the best results at the online contest will be invited to the final stage to Innopolis, the final stage winners will receive valuable prizes and souvenirs. Accommodation and meals are covered by the organizing committee.

To find out more about the Olympiad, please, visit our page: http://2018.olymp.innopolis.ru/en/

Schedule

The first stage (online contest) will be held on:

December 2, 15:00 (UTC +3),
December 17, 10:00 (UTC +3).

You may participate on both dates; the organizing committee will consider your best result. Registration is open until December 1, 2017. Participation is free of charge.

The second stage (on-site contest) will take place in Innopolis city on February 24-25, 2018.

Stay in touch

Subscribe to our Telegram account to receive quick information and reminders,
Contact us via e-mail: olymp@innopolis.ru,
Subscribe to our Facebook page.

Visit the website: http://www.spoj.com/

Coding can give more fun than computer games – an interview with Ivan Katanić

Robert Lewoń — Mon, 03 Jul 2017 12:14:04 +0200

After publishing an interview with Keshav Dhandhania we have decided to continue this project and present you other successful Spoj users, who can share their experience and all wisdom gained during their struggle with Spoj problems.

Today we present you Ivan Katanić a finalist in International Olympiad in Informatics a member of Croatian national team in computer contests and a long-time Spoj user with a #11th place in a world rank and almost 1000 solved problems.

Bubble Cup X

Robert Lewoń — Mon, 27 Mar 2017 06:43:58 +0200

Microsoft Development Center Serbia is excited to announce the start of the 10^th anniversary edition of Bubble Cup competition!

Bubble Cup is an international, ACM-style team contest aimed at university and high school students.

You can register now on BubbleCup.org. Qualifications consist of two online rounds which start on the 1 st of April and on the 1 st of May and last for 25 days each. Both online rounds will feature several problems from the Sphere Online Judge. Ten best university teams and ten best high school teams will compete in the 5 hour long finals in Belgrade in September.

Teams can consist of high school pupils or students. Students must attend the same university. Complete rules can be found here.

There are going to be some great prizes awaiting the winners! More detailed information on prizes is coming on the website soon.

We wish you best of luck in competition! Let the coding begin!

Visit the website: http://www.spoj.com/

Big languages update!

Robert Lewoń — Wed, 22 Feb 2017 08:12:17 +0100

We are happy to announce that we have updated our languages database.

There are six new languages - one of them is a Swift which was on the top of your wishlist!

Please visit the article on our blog to learn more details!

Visit the website: http://www.spoj.com/

From Spoj challenge to own startup. Short interview with Keshav Dhandhania

Robert Lewoń — Mon, 30 Jan 2017 08:56:47 +0100

We would like to invite you to a completely new series of short interviews with successful Spoj users, we will talk about their projects and their first steps in the world of coding. If you think that you have your own story that can inspire others, write to us!

Here's our first interview with one of old Spoj users: Keshav Dhandhania, a co-founder at Compose Labs, a San Francisco-based company that has just released their first project Commonlounge (with a special community for Spoj users too!).

Innopolis Open

Robert Lewoń — Mon, 05 Dec 2016 12:17:03 +0100

University Innopolis is organizing and holding Innopolis Open, an Olympiad in Informatics for secondary school students (until 19 y.o.). The Olympiad consists of two rounds — online contest and the on-site competition (held at Innopolis, Russia).

Winners of the first round will be invited to Innopolis to take part in the on-site competition. During the Olympiad, all participants will be offered a free of charge accommodation, meals and transfer from Kazan to Innopolis and back.

Winners of the second (on-site) round will receive awards and can be enrolled in Innopolis University without any admission tests.

The first (online contest) round will start on December 18 at 10.00 a.m. (UTC +3).
The second (on-site) round will take place on February 25-26 in Innopolis city, Russia.

Registration is open until December 15, 2016. Participation is free of charge. Please follow the link to register and find detailed information: https://olymp.innopolis.ru/en/ooui/16-17/

Visit the website: http://www.spoj.com/

Registrations are now open for CodeChef SnackDown - a global programming contest | Qualifier starts on 27th May 2016!

Robert Lewoń — Tue, 17 May 2016 16:49:24 +0200

CodeChef SnackDown is a multi-round computer programming contest, it will witness coders from schools, colleges, and organizations, across all ages, competing against each other on a global platform. This year there will be world's best 25 teams battling out with India's best 25 teams in Mumbai for the ultimate title of “SnackDown Champions” and hefty cash awards worth $22,500, a lucrative job offer with Directi, and plethora of cool SnackDown merchandises. The registrations are now open and the qualifying round will start on 27th May 2016. More information about the contest can be found here: https://www.codechef.com/snackdown/2016.

Visit the website: http://www.spoj.com/

Deadline24

Robert Lewoń — Tue, 26 Jan 2016 12:29:45 +0100

Passionate about algorithmic tasks? Take part in the eighth edition of international programming marathon Deadline24!

The teams of three may register up until February, 25. They will compete in the qualifying round online on February 28. For more information http://www.deadline24.pl.

Visit the website: http://www.spoj.com/

Let the programming spirit flourish! Spoj.com becomes community partner in IndiaHacks

Robert Lewoń — Mon, 11 Jan 2016 17:37:49 +0100

Spoj.com is happy to become a Community Partner of Hacker Earth in their flagship event - IndiaHacks, the world's largest developer confluence, which aims to encourage programming and celebrate the spirit of coding among developers.
It comprises of a combination of online hackathons and programming contests. This massive event commenced on January 8th, 2016 with Fintech Hackathon and Bot Challenge programming contest - two of the nine technology tracks, scheduled for the month long code fest. The other tracks open for participation for developers are Algorithms, Machine Learning, IoT, Game development, Open Source, Online Commerce, Travel and Transportation. These hackathons will see developers build unique and interesting products in only 48 hours.

The top 20 teams/individuals from the online phase will be shortlisted from each track and will be invited to the offline conference, where they will again hack for 24 hours and present their ideas to a panel of judges. Developers also get to win some cool prizes like a Trip to San Francisco, Xbox One, Go Pro 4 and much more.

So if you are developer or a coder, register and participate in IndiaHacks ->http://hck.re/x4pyxe

Visit the website: http://www.spoj.com/

NASA and Freelancer’s Space Contest

adrian — Wed, 22 Jul 2015 17:43:31 +0200

Join the NASA Tournament Lab (NTL) and Freelancer.com as they host a series of contests to crowdsource some of the most complex problems being faced by astronauts on the cutting edge of space exploration. Your contribution to these contests will be used in software simulations and by astronauts aboard the International Space Station!

For the first several contests, help build tools for the Robonaut R2, a robotic assistant used to help humans work and explore in space. Why not take this chance to be a part of humanity's journey to go beyond Earth's orbit and explore the vast wonder of space? Join the contests now.

Visit the website: http://www.spoj.com/

Enter Coding Chill-out zone

Robert Lewoń — Tue, 30 Jun 2015 16:00:23 +0200

International programming contest in the Mediterranean region.

Remote session : 26.06 - 03.07 2015
On-line session is OPEN for any registered users. Two categories: students & IT Pros. Join today and share our passion for coding. Code from your own #CodingChillout zone and rank high! Grab paid GitHub plans and Cloud computing tokens offered by Octawave.

Are you in Malta?
GOTO: On-site event in Malta on 11th July @Microsoft Innovation Center. All in relaxed and chilling climate of Maltese islands ... Just simply Enter Coding Chill-out zone, add song to the event playlist...and do what you LOVE. Register today: http://codechillout.sphere-contest.com

Visit the website: http://www.spoj.com/

CodeChef SnackDown 2015 - Code Your Heart Out

Michał — Mon, 18 May 2015 15:51:25 +0200

CodeChef SnackDown is a multi-round programming contest open to all. The multiple online rounds will culminate at an onsite grand finale, where 25 teams from across the India will be flown down to the CodeChef headquarters in Mumbai, India. For the participants residing outside India, there will be a parallel online round for the finale. While the Indian teams will compete for the cash rewards worth INR 6 Lakhs and a job opportunity with Directi, the global participants will have a chance to win exciting prizes like MacBook Pro, Drone Quadcopters, and Go Pro Cameras. So, register your teams now and strengthen your chances of winning.

Visit the website: http://www.spoj.com/

Ta-dah!

Michał — Tue, 10 Mar 2015 09:09:00 +0100

We present the long-awaited new, fresh, and crispy design of SPOJ! It's taken us a while to get here since 2004, but hey, it looks good - doesn't it? There's now a new feature for tagging and grading problems. We are also working to make SPOJ as mobile-friendly as possible. Stay tuned, because there are many more surprises to come!

Visit the website: http://www.spoj.com/

Goodbye Pyramid

Robert Lewoń — Fri, 06 Mar 2015 15:46:47 +0100

During the last six months, we have been gradually migrating our "checkers" (servers which execute submissions) from old to new machines. The procedure required some care since the new machines have significantly greater processing power. The main difficulty was adjusting the time limits for problems: in general, the new machines seemed to be more "tolerant" of slow solutions than the old ones. Over the 10 years of existence of SPOJ, our great community has produced over 13.5 million submissions (10 million of which on the old checkers) and we didn't want to rejudge all of them. So, we designed an algorithm for recalculating submission running times by interpolation. Data for reliable interpolation came from a real rejudge of a representative sample of 5% of the submissions, i.e., 511,000 submissions have been rejudged over the past six months. At the end, we changed the time limits of test cases keeping them in relation to running times of solutions.

read more

Despite our best efforts, we cannot guarantee that all recalculated times are completely accurate. If you are concerned about your score, we encourage you to resubmit your solution. If you are an author of the problem, please verify the time limits of test cases - especially when your problem was designed to distinguish fast and slow algorithms!

To honor the very long service of our old checkers, we would like to share a little more of their background story with you. The SPOJ website is developed and maintained by Sphere Research Labs. The "sphere" is cited in described in many sources as the perfect three-dimensional shape - the model of beauty and excellence. The naming convention for our computing clusters is also based on spatial geometry: our servers' names include "Cubes", "Cones", "Pyramids", and "Prisms".

SPOJ started out in 2004 with a bunch of vintage 266MHz machines named "Cones". These were very soon completely replaced by the freshly withdrawn "Pyramid" cluster. The single computing unit for "Pyramids" was the Intel Pentium III 733 MHz, and submissions at SPOJ were allowed to use up to 256MB of memory. The slowness of Pyramids by today's standards was often seen by problem setters as an advantage: it was possible to distinguish fast algorithms from slow ones without creating enormous datasets. The new "Cube" cluster consists of modern and fast Intel Pentium G860 CPU's and your submissions are run with a 1536 MB memory limit.

The chart below shows the number of pieces of code executed annually on the "Pyramid" cluster, between 2004 and last year. That's exactly 10074843 submissions in total. Since 2012, you can also see how many submissions were executed using the "Cube" cluster. The two clusters were almost equally loaded in 2014.

The last Pyramid submission was executed on 2015-03-02 at 10:51:35. We turned off the Pyramid cluster on the same day at noon GMT+1.

We hope that when we share the next chart with you at some point in the next 10 years, the submission rate will still be increasing at least as quickly as in the last decade!

Visit the website: http://www.spoj.com/

Lambda Days 2015 Challange

Robert Lewoń — Sun, 15 Feb 2015 12:45:44 +0100

For the second year in a row Lambda Days come to Kraków to bring together people passionate about functional programming. The tickets are out and the only way to attend at the moment is to get high score in their special programming contest. If you are interested in participation visit http://lambdadays.sphere-contest.com.

Visit the website: http://www.spoj.com/

Banning cheaters

Piotr Kąkol — Wed, 03 Dec 2014 16:09:47 +0100

We have intensified banning cheaters (users who copy codes from the internet and submit them here). Soon all of them from "Cheaters" thread on forum will be banned. If you are a cheater you can avoid ban by disqualifying all your cheating submissions until we get to you. After mentioned thread all users from top100 (and then top256) will be x-rayed.

Visit the website: http://www.spoj.com/

CONSTANT

Piotr Kąkol — Sun, 30 Nov 2014 20:30:56 +0100

Please check out a new contest CONSTANT. It's dedicated to problems in which you have to evaluate as many digits as possible of famous constants like π, e or φ.

Even if you are not interested, you may find there a link to the world records in this field. You may be surprised.

Visit the website: http://www.spoj.com/

Do you teach algorithms, data structures or programming paradigms?

kuszi — Sat, 30 Aug 2014 16:00:40 +0200

This is just a short message to remind you about SPOX which is dedicated for your academic activities.

Visit the website: http://www.spoj.com/

Codecha.org

kuszi — Thu, 27 Feb 2014 12:41:24 +0100

Codecha (True Programmers' CAPTCHA) - the new project based on Sphere Engine - has just started.

Visit the website: http://www.spoj.com/

Badges for SPOJ by Ricardo Bittencourt (ricbit)

kuszi — Wed, 05 Feb 2014 10:48:35 +0100

Ricardo Bittencourt (ricbit) made SpojTweet to track your progress on SPOJ, and give badges for your achievements. Please have a look at an example page from the site, an exemplary tweet sent by a site, Ricardo's SPOJ forum post and more SPOJ tools.

Visit the website: http://www.spoj.com/

Are you a novice in programming?

kuszi — Sat, 14 Dec 2013 23:07:47 +0100

Please consider Simple Programming Problems. Comments and suggestions are very welcome here.

Visit the website: http://www.spoj.com/

Programacion Competitiva Bolivia

kuszi — Wed, 28 Aug 2013 17:41:25 +0200

A new subSPOJ for those who would like to try problems from Bolivian OI, ICPC and other contest. Please join bo.spoj.com.

Visit the website: http://www.spoj.com/

High School Programming League 2012/13 final results. The winner is Tomasz Rewak. Congratulations!

kuszi — Thu, 21 Mar 2013 21:08:33 +0100

Top 5 contestants:

1	Tomasz Rewak	II Liceum Ogólnokształcące im. Stanisława Wyspiańskiego w Legnicy, Poland
2	Mario Lipovsky	Spojená škola Novohradská, Slovakia
3	Aleksandar Ogrizovic	Gimnazija "Veljko Petrović", Serbia
4	Tomasz Zwornicki	I Liceum Ogólnokształcące im. Tadeusza Kościuszki w Łomży, Poland
5	Wojciech Zieliński	Zespół Szkół UMK: Gimnazjum i Liceum Akademickie, Poland

more ...

Top 3 Teams:

1	Gimnazija "Veljko Petrović", Serbia (Coach: Duško Obradović)
2	Zespół Szkół UMK: Gimnazjum i Liceum Akademickie, Poland (Coach: Anna Beata Kwiatkowska)
3	Zespół Szkół Techniczno - Informatycznych w Gliwicach, Poland (Coach: Daniel Kuśka)

more ...

Visit the website: http://www.spoj.com/

ITRIX Online Programming Contest

kuszi — Wed, 27 Feb 2013 14:05:01 +0100

ITRIX 2013 is a 5-hour ACM-ICPC style online programming competition organized by College Of Engineering Guindy, India. Contest starts 2013-02-27 16:30:00 SPOJ time. All college students are invited to participate.

Visit the website: http://www.spoj.com/

SPOX Beta – the online grader for your programming courses

kuszi — Sat, 29 Sep 2012 16:31:37 +0200

It is our pleasure to announce a new system dedicated to teaching programming. SPOX (http://spox.spoj.pl) has been built upon the same engine as SPOJ, but dedicated to teaching in the context of private lessons or regular courses at different levels, starting from beginners to advanced university students.

Visit the website: http://www.spoj.com/