Home - DMOJ: Modern Online Judge

Welcome to the DMOJ!

The DMOJ is a modern contest platform and archive of programming problems. It's also entirely open source.

So far, 8882 developers have submitted to 1168 problems a total of 455717 times, using 66 languages.

If this is your first visit, please register an account. Then, try the Hello, World! problem.

Blog
Events

News

Don Mills Programming Gala 2017

Phoenix1369, WallE256, Kirito posted on April 19, 2017, 7:300

As the academic year comes to an end, we'll be holding our final DMOPC in the form of the Don Mills Programming Gala.

This event will take place at Don Mills C.I. on Monday, May 15^th.

The contest will be split into three divisions of increasing difficulty, with prizes awarded to the top competitors. For interested competitors unable to attend the on-site event, we will also be hosting mirrors of the divisions, open for anyone to participate in.

Space is limited, so sign up soon! More details and registration options may be found here. You can find the results of last year's DMPG here.

Registration is now closed. Thank you for your continued interest.

TLE '16 April

ZQFMGB12, d posted on April 14, 2017, 11:590

Thanks for participating in the TLE '16 April contest!

The winners are:

Editorials for each of the problems will be uploaded to the respective problem pages.

We hope you enjoyed the contest, and thanks to all who participated in the TLE rounds throughout the 2016-17 school year!

We're excited to invite you to the eighth Trudeau Logic Evaluation of the 2016-17 school year!

This TLE round will be the last online round of the 2016-17 school year!

The TLE '16 April contest will be a 3-hour virtual contest, which will allow contestants to participate in any 3-hour window from 12:00 PM EDT to 11:00 PM EDT on April 20, 2017. Please see the contest page for more details.

See you soon and good luck!

TLE '16 March

ZQFMGB12, d posted on March 21, 2017, 8:410

Thanks for participating in the TLE '16 March contest!

The winners are:

Editorials for each of the problems will be uploaded to the respective problem pages.

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

We're excited to invite you to the seventh Trudeau Logic Evaluation of the 2016-17 school year!

The TLE '16 March contest will be a 3-hour virtual contest, which will allow contestants to participate in any 3-hour window from 12:00 PM EDT to 11:00 PM EDT on March 23, 2017. Please see the contest page for more details.

See you soon and good luck!

CCC '17 Problems Posted

Kirito posted on March 6, 2017, 1:551

All problems from this year's CCC have been added. You may access them here.

Editorials for most problems can be found on their respective pages — please remember to use these editorials only when stuck, as copy-pasting code from them will see you permanently banned from submitting that problem.

Hope you enjoyed this year's CCC!

Point System Rework

posted on Feb. 21, 2017, 6:352

Over the past few weeks, we have been trialing a new system for ranking users based on points. After a number of revisions based on suggestions from those enrolled in experimental features, we feel the system is stable enough as-is to make public.

Why a new system?

The old system over-awarded those who spent time "farming" a large number of easy problems, and under-rewarded those who spent time figuring out more complex solutions. The new system hopes to strike a balance in ranking between users who solve many problems, and users who solve fewer — but harder — problems.

How are points calculated?

In short, the new points system takes the weighted sum of the top 100 submission scores on distinct problems. The score of the $i^{th}$ problem is weighted by $0.95^i$ . Formally, where $S$ represents sorted scores and $P$ a user's base points,

$\displaystyle P = \sum^{\min(99,\ \left| S |\right)}_{i=0} 0.95^i \cdot S[i]$

To not over-penalize users who have dedicated time to solving many problems, an additive adjustment $B$ is made to the base point value. Where $N$ is the number of problems a user has a fully-accepted solution on,

$\displaystyle B = 150\cdot(1-0.997^N)$

A user's point score is then the sum $P + B$ .

How can I see a problem's contribution to my points?

A new table has been added to the Problems tab of profile pages, which displays the 100 submissions used in the generation of their point score, as well as their weights.

Richmond Green Programming Contest 2017

chenj posted on Feb. 16, 2017, 1:540

We invite you to the Richmond Green Programming Contest 2017, where you can practice for the upcoming CCC!

This contest will have the same format as the CCC, but should be slightly easier than the senior division. RGPC will be a 3-hour virtual contest, allowing users to participate in any 3-hour window from 12:00 PM EST on February 17, 2017 to 11:59 PM EST on February 19. Please see the contest page for more details.

Good luck on the CCC!

TLE '16 February

ZQFMGB12, d posted on Feb. 15, 2017, 10:140

Update: Thanks for participating in the TLE '16 February contest!

The senior division winners are:

The junior division winners are:

Editorials are located at each individual page.

We hope you enjoyed the contest! See you next month!

We're excited to invite you to the sixth Trudeau Logic Evaluation of the 2016-17 school year!

In order to prepare students for the Canadian Computing Competition (CCC), this round will have the same format as the CCC. Additionally, there will be both a junior and a senior division.

The TLE '16 February contest will be a 3-hour virtual contest, which will allow contestants to participate in any 3-hour window from 9:00 AM EST to 11:59 PM EST on February 20, 2017. Please see the senior contest page or the junior contest page for more details.

See you soon and good luck on the CCC!

DMOPC '16 February Contest

Phoenix1369, WallE256, Kirito posted on Feb. 10, 2017, 9:001

Thanks to everyone who participated in this month's DMOPC!

Congratulations to the winners:

We hope you enjoyed the contest! See you next month!

We also encourage you to complete this feedback form so we can improve in future contests.

On Tuesday, February 14th, we'll be hosting the February Don Mills 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 Feb. 14th and noon EST of Feb. 15th. Please see the contest page for more details.

See you soon!

TLE '16 January

ZQFMGB12, d posted on Jan. 16, 2017, 12:460

We're excited to invite you to the fifth Trudeau Logic Evaluation of the 2016-17 school year!

The TLE '16 January contest will be a 3-hour virtual contest, which will allow contestants to participate in any 3-hour window from 12:00 PM EST to 11:00 PM EST on January 19, 2017. Please see the contest page for more details.

See you soon and we hope you will gain many internet points!

Mackenzie New Year's Contest '17

aurpine posted on Jan. 6, 2017, 10:310

We invite you to the Mackenzie New Year's Challenge 2017. A 36 hour challenge consisting of 6 problems in varying difficulty. This contest will take place on Saturday Jan 7th 12pm until Sunday Jan 8th midnight.

See the contest page for more details. Enjoy and happy holidays!