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News

JOEL 1.5!

edgar posted on Aug. 18, 2026, 12:17 p.m. 0

Well, there's been a ton of news since the last update — about time, especially after marc promised it back at 300,000 submissions. Here's a summary of the most important ones.

New: Database Mode

JOEL isn't just for programming anymore: you can now also practice SQL and MongoDB.

  • New "Database Problems" tab in the problem list, separate from the programming one. They have their own category and their own ranking (/users/sql) — they don't add to your programming points.
  • A database problem can have several questions in a row about the same database, each scored separately.
  • Schema explorer: from the problem page you can browse the database's tables and columns, with a visual diagram of how they relate to each other.
  • Besides querying data (SELECT / find), you can now also solve INSERT and UPDATE problems — always completely safely, without ever touching any real data.

Institutions

  • Institutions (for example, "Institut Sabadell") now have their own public page, separate from the teams/classes that belong to them.
  • The institution's flag and name are shown in user lists and contests, without repeating if you're on several teams from the same institution.

Contests

  • Organizers can freeze the scoreboard: from a given moment on, submissions show as made but whether they're correct isn't revealed until it's unfrozen.
  • The first person to solve each problem is marked with a special color, and the cell "flashes" if it was just solved.
  • The ranking now also shows how many incorrect attempts each person has made on each problem.
  • New "team contest" option: teachers can enable it so that, when joining, each participant picks their own team name. That name (rather than the username) is what shows on the ranking, and once chosen it can't be changed.

Gacha

  • Revealing a prize is now much more spectacular: lights, sounds, particles, confetti — all worthy of Genshin Impact.
  • New daily bonus: the first time each day that you solve a problem you hadn't solved before, you earn 5 free GachaPoints (a free pull). A marker in the corner of the screen tells you if you still have it available.

Guides and help

  • Many introductory problems now have their own help guide (marked with a graduation-cap icon), adapted both to your language and to the programming language you're using.
  • Fixed a thousand quirks from the first version of the hint system that made it take up 80% of the database. Asking for a hint is now instant, with no page reload.

Other improvements

  • Translations reviewed and expanded in Catalan, Spanish, English, German, and Chinese (the last one with AI).
  • Various security, efficiency, and small visual bug fixes across the site.

By the way, let me introduce myself — I'm JOEL's new admin, and I'll mainly be handling the Database side and systems stuff, so you'll see less of me than the other two ;)

Conclusion of the 2nd Programming League

srivas posted on Feb. 21, 2026, 7:48 p.m. 0

The 2nd Programming League has ended with these winners:

First division (open to everyone):

  • 1st.- Img (Institut TIC de Barcelona) - 233 points
  • 2nd.- rotohail404 (Institut Sabadell) - 173 points
  • 3rd.- Javier_Lázaro (Bernat el Ferrer - Molins de Rei) - 117 points
  • 3rd.- Joan_Lorente (Bernat el Ferrer - Molins de Rei) - 117 points

Second division (restricted to first-year students):

  • 1st.- a25guerodmar (Institut Pedralbes de Barcelona) - 167 points
  • 2nd.- HX04 (Institut TIC de Barcelona) - 165 points
  • 3rd.- SlaavKo (Institut TIC de Barcelona) - 155 points

Congratulations to the winners and thanks to all participants.

We hope you enjoyed this experience and we'll see you in the next edition.

Introduction

marc posted on Dec. 2, 2017, 6:00 a.m. 2

Welcome to the Jutge Online Educatiu Lliure (JOEL), home of the Jutge Online Destinat a l'Ensenyament amb Retroacció (JODER), an Online Judge based on DMOJ ( dmoj.ca )

If you're new, check out the Student Guide.

you can start with this introductory problem.

If you want to know more about JOEL, check out my FAQ.

The Programming League is back

srivas posted on Jan. 8, 2026, 4:54 p.m. 0

The Programming League continues now that the holidays are over, and round 7 will begin on January 10th.

By now you know how to program quite a bit more than at the start, and the ProgramaMe regional qualifier is getting close, so it's time to grit your teeth and give it your all. We've turned the difficulty up a notch on the problems (thanks Marc!), so think them through carefully before you start coding or you'll be swimming in TLEs and MLEs!

We hope you really enjoy the challenges we've prepared for you.

Happy 2026 and good luck!

Merry Christmas everyone!

srivas posted on Jan. 8, 2026, 4:53 p.m. 0

JOELNadal

The Programming League is taking a well-earned break, but it'll be back with round 7 on January 10th, 2026.

Here are the updated standings at the end of round 6.

In the first division standings there's a two-way tie for the lead with a perfect score, but with several chasers ready to pounce on any slip-up. The second division standings are even more exciting, with 19 students tied for the top score.

The whole JO-EL team wishes you good luck for the coming year 2026 and a wonderful holiday season.

See you when we're back!

We've reached 300,000 submissions!!!

srivas posted on Nov. 6, 2025, 2:36 p.m. 0

300000

Today, November 6th at 9:17am, while some people were shipwrecked outside in a heavy downpour, someone made submission number 300,000 and, of course... it turned out to be a failed submission, again! (did they get shipwrecked too?)

This time we had everything going for us: the moment was approaching, we opened an easy test contest with a Hello World! that everyone can get right on the first try. What could possibly go wrong?

But it wasn't meant to be, and this time there won't be any prize either.

See you at submission 400,000!

PROGRAMMING LEAGUE - We kick off on Nov 8th

srivas posted on Oct. 27, 2025, 7:59 p.m. 0

Second season of the Programming League

logo_lliga

The second season of the League is warming up its engines and already has a start date: November 8th!

What's new this edition:

  • There will be 12 rounds
  • Rounds will be smaller (2 or 3 problems), but more frequent (1 every week).
  • They'll open at midnight on Saturdays
  • We have a League logo now

Next week we'll share more news. Stay tuned!!!

FP PROGRAMMING LEAGUE - SEASON 2 - TEASER

marc posted on Oct. 8, 2025, 12:47 a.m. 0

Hi! Several institutions have come together to move forward with last year's FP Programming League project. So we're happy to announce there will be a SECOND SEASON of the FP Programming League!

It'll start very soon, and we have 3 surprises ready to celebrate the start of the league.

For students:

If you're interested in taking part or want to know how it works, ask your school to get in touch with the organizers so you can join in.

For teachers:

If you'd like to know how to use JOEL or the League to help with your programming modules, get in touch with the organizers too.

Very soon (very soon!) we'll tell you the rounds, host institutions, and how the league works. You can check out here how last year's League went:

https://docs.google.com/presentation/d/14fyKTrqAtS401gZ4sVI2Fhdgbu0q019dOToAD1mGk5E/edit?usp=sharing

First surprise: Java 25!

We've updated JOEL to make it compatible with Java 25. This update, which improves on the previous Java 11 version, means JOEL can now run code written in Java 17, Java 21, or Java 25, taking advantage of the Quality of Life improvements recently added. So if you use Java, we recommend switching your preferred language to Java 25.

See you very soon with more news!

XVIII Codejam - 2025

marc posted on Feb. 4, 2025, 9:51 p.m. 0

Hola!

El dia 12/02/2022, de 16:00 a 19:30 es celebra la Codejam 2025! Aquesta és la edició num XVIII de la Codejam.

La Codejam és un concurs de programació de 3 hores, a on els concursants intenten resoldre la major quantitat de problemes possibles. En aquest sentit, si la Lliga de Programació és una Lliga, la Codejam és com si fos la Copa!

A les 15:50 es fara una petita presentació sobre el concurs, com funciona, i com fer servir la plataforma, mitjançant aquest canal de youtube

També es penjaran unes petites instruccions, que teniu aquí

Sort!

JOEL 1.4!

marc posted on Aug. 20, 2024, 6:12 p.m. 0

Benvinguts a la versió 1.4 de JOEL!

S'han fet algunes millores en aquesta versió

  • Habilitat Sistema d'ELO
  • Habilitat Concurs Rankeds
  • Habilitat Sistema de Lligues
  • Els Gachapoints ja no donen errors d'arrodoniment per float

Més informació sobre els nous sistemes en breu!

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Comment stream

  • AlejandroMuñoz → alejandro VS alexandro
  • Elvin_Po_Ma → Dia de la Setmana
  • ssubirats → Hola Mon!
  • marc → The IES Sabadell Incident
  • markiduro → The IES Sabadell Incident
  • Morodeoro → Calcular factorial
  • Morodeoro → Te han Expulsado de la Hermandad
  • perePro → Amistats difícils de comptar
  • marc → Te han Expulsado de la Hermandad
  • srivas → Tipus de vi
RSS / Atom

New problems

  • Bases de Dades: INSERT bàsic (Employees)
  • Bases de Dades: UPDATE bàsic (GroupByTest)
  • Bases de Dades: UPDATE en un sistema de reserves (Hotel)
  • Bases de Dades: UPDATE en un joc de comerç (Traders)
  • Bases de Dades: INSERT en un esquema més gran (Chinook)
  • Bases de Dades: INSERT amb claus foranes (Knights & Dragons)
  • Bases de Dades: Problemes més difícils
RSS / Atom

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