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Commenting restricted.

by jargon on Oct 27, 2015 - 12:46:00 am UTC
  • (4/0)
Effective immediately, you must solve aplusb before you may post a comment.

Sorry for the inconvenience.

Woburn Challenge round 1 results are now available!

by Alex on Oct 20, 2015 - 11:28:15 pm UTC
  • (3/0)
Thank you all for participating! For this round, we had 178 registered competitors from over 29 schools. There were 6 perfect scores in the senior division and 3 perfect scores in the junior division. The problems had varying difficulties, and hopefully there was something that challenged every one of you. If not, look forward to even more challenging puzzles in the rounds to come.

Click here for full results to the contest. Problems, solutions, and test data are now available here.

The senior division prizewinners for this round are:
  • Timothy Li of Don Mills Collegiate Institute ($200)
  • Ahmed Sabie of Glenforest Secondary School ($100)
  • Jeffrey Xiao of University of Toronto Schools ($50)
  • Bill Zheng of Richmond Green Secondary School ($50)
  • Brian Chau of Woburn Collegiate Institute ($50)
The junior division prizewinners for this round are:
  • Sunny Lan of Richmond Hill High School ($50)
  • William Huang of Woburn Collegiate Institute ($25)
  • Jamie Pinheiro of St. Francis Xavier Secondary School ($25)
Congratulations to all of you! These prizes will be distributed as Mastercard gift cards, and we will be contacting your teachers shortly about sending them out. If you haven't won a prize, keep on practicing! We have many more prize opportunities for you throughout the year.

Re-introducing: Woburn Challenge!

by Alex on Oct 06, 2015 - 5:30:32 am UTC
  • (5/0)
Edit: The contest is over! Many thanks to all of you who participated. We will be posting prizewinners and analyses to all of the problems shortly. Check here, as well as our website periodically!

Edit 2: The problems have been cloned to the main judge. Feel free to submit to them for practice while we work on publishing results and analyses.
Junior Problems: J1, J2, J3, J4
Senior Problems: S1, S2, S3, S4


From the mid-1990s to the early 2000s, the Woburn Challenge was an annual computer programming competition hosted and run by Woburn C.I.'s Programming Enrichment Group. We feel that the time is right to relaunch this free and fun competition for aspiring computer science students in Canada. This year, we're prepared to give out thousands of dollars in prizes to top-performing primary and secondary school students in Canada. If you are a Canadian primary or secondary school student (grades 1-12), you must follow the registration instructions at to be officially eligible for prizes. While only this group of people can receive prizes, everyone is welcome to participate in the online rounds as observers.

This year, we're hosting 4 online rounds (each with a prize pool of over $500) and an in-person invitational finals at the end of the school year (even larger prizes to be announced!). The rounds will take place in October, December, February, April, and early June (for the finals).

Online Round 1

When: Friday, October 16th, 2015 from 3:30 pm to 6:30 pm ET
Where: The PEG Judge interface (
Format: 2 divisions, 3 hours, 4 problems, infinite submissions, and live feedback.
  • Top 3 Junior division winners: $50, $25, $25
  • Top 5 Senior division winners: $200, $100, $50, $50, $50

Full format and rules can be found at:
For more details, visit For questions, email [email protected].

Good luck!

I have removed all the old SHA-1 hashes, so if you didn't login or change your password during the last 30 days as instructed by a previous announcement, you will no longer be able to login.

If you can't login, please use the forgotten password feature to reset your password and set the new bcrypt hash.

The 30 day deadline given in has almost expired.

If you haven't logged in or changed your password since the announcement, you must do so by tomorrow, otherwise you will not be able to log in and will need to use the password reset feature to reset your password before you log in again.

Please note that simply browsing the site while logged in is not sufficient. You must log out and back in again so that your password will be hashed using the new hashing algorithm.

IOI 2015 problems have been (partially) added

by Alex on Sep 05, 2015 - 11:16:47 pm UTC
  • (3/0)
The non-interactive problems from IOI 2015 have been added. Please report any issues you find.

Day 1, Problem 1 - Boxes with Souvenirs
Day 1, Problem 3 - Teams
Day 2, Problem 1 - Horses
Day 2, Problem 2 - Sorting

The PEG Judge has switched to a more secure password hashing scheme. From now on, your passwords will be hashed securely using bcrypt.

Within the next 30 days, if you log in or change your password, the new password hash will be activated for your account. Please note that we cannot generate the new password hashes without you entering your password on the site, because the old passwords are still hashed (and not stored in cleartext).

In 30 days from now, the old, less secure hashes will be deleted from the database. If you do not log in or change your password within 30 days of this announcement, you will not be able to log in and will need to use the forgotten password feature in order to reset your password.

CCO 2015 Problems Added

by Alex on Jun 05, 2015 - 11:08:55 pm UTC
  • (1/0)

Suggest some tags!

by jargon on May 02, 2015 - 3:42:13 am UTC
  • (0/0)
Better problem tagging infrastructure is on its way, and we need help figuring out which tags would be useful!

Please reply to this post with suggestions.

CodeIgniter upgraded to 3.0

by bbi5291 on Apr 30, 2015 - 6:12:58 am UTC
  • (1/0)
This is a major change to the PEG Judge's codebase. I have tested to make sure most features on the site are still working, but some may be broken. Please report bugs here.

In addition, you might need to clear your cookies before you can log in again.