EGOI is over. The Closing Ceremony and Goodbye Blogpost are online.

Cookies for twins and Christmas presents in June

On Wednesday, participants faced the first of two contests

So far, EGOI has been all fun and games. On Wednesday, at 10:00 in the morning CEST, things got serious. The girls of the first EGOI sat down in front of their computers and coded away for the first part of the official competition. There were four tasks to solve, one more tricky than the other. As is the custom at Informatics Olympiads, the algorithmic problems were wrapped up in creative prompts telling a little story.

In the first task, participants met someone who should be on holiday in summer: Santa Claus. However, since preparations for Christmas can’t start early enough, Santa is already trying to figure out how to buy some presents which he can divide evenly among all the children. The issue is that Santa cannot yet know how many children there will be. He only knows that the number will be within a certain range and has a rough idea of the minimum amount of presents he could divide between the children.

After checking the correctness of Santa’s calculations, the participants briefly turned into matchmakers, assigning integers to a group of friends standing in a line and sending each couple sharing a number on a date - if the two happen to stand next to each other in the line, that is. This puzzle was followed by a party. The participants were tasked with organizing equally tasty cookies for two twins celebrating their birthday. This may sound straightforward, but the cookie company providing the cookies has serious issues with its delivery service (employees seem to be seriously underpaid, since they eat up all but one cookie per order) and their products’ quality is quite inconsistent. Every cookie is unique, with an integer “tastiness value” inside a certain range.

In the final task, the participants were sent to the alps. There, a farmer had the glorious idea of going on a hiking excursion not too long before sunset, but he lost his cows along the way. The success of his rescue mission in the dark relies on lanterns purchased at each mountain top. However, the lanterns only illuminate a limited range of altitudes. Seeing no way out of his dangerous situation, the farmer requested the help of the only people who could pave a brightly lit way for him: EGOI participants. As nobody received a full score in this task, we can expect that the farmer is still missing some cows. But he surely managed to get most of his herd back together with the help of the brave young computer scientists!

After the contest was completed at 15:00 CEST, the participants had the rest of the afternoon (or whatever time of the day it was in their time zone) to watch the solution videos recorded by the scientific committee, discuss their approaches with the leaders and each other and check their performance on the scoreboard.

The day was rounded off by a game night where participants could pick between games such as the East Asian inspired Swiss card game “Tichu” or “Unrailed”, where they had to collaborate to build train tracks fast enough to keep an out of control freight train from exploding. At first, the train did explode several times, but with experience came a higher life expectancy for the small team of amateur railway engineers. The game “Among Us” enjoyed some popularity. Participants and guides boarded a virtual spaceship, wary of the homicidal impostor among them. Whether helping out Santa, leading farmers across alpine peaks, shopping for cookies, or tinkering with trains tracks and spaceship infrastructure - it was a day of many quests for our algorithmic adventurers!

Throwback to tuesday: In just one day, Team Hungary climbed a mountain on the border to Austria, visited a medieval castle and attended one team member’s graduation! (Source: John von Neumann Computer Society)
Throwback to tuesday: The Dutch team also had a very active day - practising, canoeing, a nice restaurant dinner and, of course, biking. You can see videos of their day on the Swiss Olympiad in Informatics social media - in this picture, they are socializing on Discord during Tuesday’s evening program.
Team Ukraine ready and motivated for the challenge ahead!
The contest across the world: Japan…
…Mexico… (Source: Olimpiada Mexicana de Informática)
…and Spain…