Congratulations to the winners of the first GlobeX Cup!

The winners of the junior division of GlobeX Cup '18 are:

1. ericlong2 (perfect score)
2. alvin123321 (perfect score)
3. Fungucide (perfect score)

The winners of the senior division of GlobeX Cup '18 are:

1. zhouzixiang2004 (perfect score)
2. aeternalis1 (perfect score)
3. KevinWan (perfect score)

Once again, congratulations to the winners this year. An email has been sent regarding your awards.

Editorials to problem statements will be posted within the next two months.

We hope that you enjoyed the contest and hope to see you again next year!

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We're excited to invite you to participate in the GlobeX Cup!

The contest will take place on December 15-16 for a 24-hour window. Once you enter the contest, you will have 3 hours to solve the designated problem statements. It will be split into two divisions of increasing difficulty, with more than $1000 in prizes awarded to the top competitors.

Contest

There are two different divisions featuring problem difficulties from elementary to advanced. To determine which division suits you the best, try the junior sample and the senior sample.

Registration

Please fill out this form in order to register for the contest and be eligible for prizes.

Prizes

• 1st Place Junior & Senior: Wolfram|One + Wolfram|Alpha Pro
• 2nd Place Junior & Senior: Any JetBrains Product
• 3rd Place Junior & Senior: Free Admission to TOHacks

Contact

For any inquiries, please email [email protected] or message our Instagram page GlobeXCup.

Details

WEBSITE | DETAIL / RULES | TEAM | SPONSORS

We're excited to invite you to Another Contest 3, the third contest in the Another Contest series!

After seeing the second contest be run, we're adding a fourth problem to the contest and shifting the difficulty curve to be more friendly for less experienced participants. You can see the full parameters of the contest on the contest page.

Good luck to all participants!

Thanks for participating in the first LKP Programming Contest!

The winners are:

1. bruce
2. y0105w49
3. neal
4. SourSpinach
5. arararararararararararararagi

We hope you enjoyed the contest!

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On Saturday, November 17th, we'll be hosting the first LKP Programming Contest!

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between 16:00 EST of Nov. 17th and 16:00 EST of Nov. 19th. Please see the contest page for more details.

See you soon!

Thanks for participating in the DMOPC '18 November contest!

The winners are:

1. y0105w49
2. neal
3. RainbowRating
4. Eliden
5. KevinWan

Editorials for each of the problems have been uploaded to the respective problem pages.

We hope you enjoyed the contest, and see you next month!

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On Tuesday, November 13th, we'll be hosting the November DMOJ Monthly Open Programming Contest!

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between noon EST of Nov. 13th and noon EST of Nov. 14th. Please see the contest page for more details.

See you soon!

We're excited to invite you to Another Contest 2, the second contest in the Another Contest series!

After seeing the first contest be run, we're changing up the format a little bit to make the contest experience more pure. Firstly, we're making the contest rated for everyone who opens the contest. Secondly, the scoreboard will be hidden for the duration of the contest. You can see the full parameters of the contest on the contest page.

We'll also be tuning the difficulty of Another Contest 2 to be lower than the difficulty of Another Contest 1.

Good luck to all participants!

This is the first of a series of blog posts about the task `meetings' from IOI18. It is also available in a contest that will take place in conjunction with these posts.

We chose this problem as an experiment to see whether we can present a single problem in a way that it covers a lot of useful knowledge for a contest related topic. In this aspect, meetings is a great task in that it starts with dynamic programming, then moves into range queries and tree constructions, and finally, finishes it off with geometric data structures.

Furthermore, the setting of meetings is as classical as a data structure problem can get: you get a static array, and you query about some statistic on its subintervals. This is a setting that has been viewed as "completely understood" by most competitors who aim for top 40 or higher at the IOI since around 2005. However, this problem was given, and had 0 solvers. I've also heard several past contestants who placed in the Top-3 at IOIs refer to this problem as "Godly", so that's another reason to discuss it in more details.

In short, the ideas underlying meetings are extremely novel, especially given how well understood the topic is. Also, if mechanically you can solve meetings in 2 hours reliably, you shouldn't have trouble with most data structural topics.

Continue reading...

Recently, we have rolled out Two Factor Authentication! You can enable it on your edit profile page in order to make your account more secure.

For those that do not know how, the following are the steps that you can take:

1. Install Google Authenticator, Authy, or any other similar apps that provide the functionality.
2. Scan the QR Code with your device, or enter the code provided manually.
3. Enter the code shown by your device to sanity check and complete the enabling process.
4. Henceforth, your device should provide the 6-digit code that will be used for Two Factor Authentication.

Please note that the time on your device is required to be correct as the codes provided are time-based.

Recently, on the ACC1 (Another Contest), there was a fairly high profile attempt of utilizing fake accounts.

While such attempts may be done partly for humor, the nature of the DMOJ contests (with their long open durations) means such behavior could completely destroy the usefulness of the ranking system. We reached out to the likely users (according to xiaowuc1 it was not too hard to identify who they were by reading their code), and they agree with us about the seriousness of their actions. Please see below for their message.

In fact, we would like to use this opportunity to encourage users who would like to compete at national levels (or higher) to add their real-world information onto the about pages of their profiles. Yes, this adds additional stress for doing the contest (due to feeling like being watched), but it's also an essential part of the contest process.

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Hello DMOJ,

We wanted to apologize for cheating on Another Contest 1 (10/12/2018). We took the contest as a team of 3 people with 3 computers on a fake account (y0105vv49). We understand that this is very unsportsmanlike, as it directly affects the rankings of real contestants taking the contest legitimately and sets a bad example for other users. Some of us have previously been reprimanded for this issue before, but we evidently failed to learn our lesson. We won't do this again. If there's any contributions to the DMOJ community we can make to make up for this, such as setting a contest, we'd be eager to volunteer our time.

Andrew He, Kevin Sun, Yinzhan Xu

Update: As of 12:07pm EDT today, the affected users and their data should be restored. If there is any problem, please don't hesitate to contact us on slack or at [email protected] Again, we apologize for the inconvenience.

At approximately 10:10am EST today (October 15th), we experienced a database error that led to the loss of several thousand user accounts, as well as related submissions. We are in the process of restoring from a backup from yesterday (October 14th), 8pm EST. Users whose accounts were affected will be rolled back to their backed up state, while users who are not should see no changes.

To prevent possible collisions while restoring, we have temporarily blocked logins and new registrations.

We are sorry for any inconvenience this may cause.

Thanks for participating in the DMOPC '18 October contest!

The winners are:

1. xiaowuc1 (perfect score)
2. d (perfect score)
3. whzzt (perfect score)
4. fjzzq2002 (perfect score)
5. yjq_naiive (perfect score)

Editorials for each of the problems have been uploaded to the respective problem pages.

We hope you enjoyed the contest, and see you next month!

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On Tuesday, October 9th, we'll be hosting the October DMOJ Monthly Open Programming Contest!

Anyone with a DMOJ account is welcome to participate, and anyone without one is welcome to register and participate.

Contestants may participate in any 3-hour window between noon EDT of Oct. 9th and noon EDT of Oct. 10th. Please see the contest page for more details.

See you soon!