EGOI 2025

Monday, July 14 (Laetitia)

The whole Swiss team met at Zurich main station at 10.45 on Monday morning. Myriam was already in Bonn as she had been at the CEOI in Romania. Before getting on our train, we grabbed some lunch. Our team leaders had chosen a direct train to avoid any risk of missing a connection (we were taking a German train).

The journey started off smoothly, and by the time we reached the last stop before Bonn, we were running only about 10 minutes behind schedule. But just 20 minutes away from our destination, the train unexpectedly came to a halt at a station it wasn’t even supposed to stop at.

For a while, we had no idea what was happening. The conductor only got in touch about 10 minutes later and explained to us that lightning had struck something on the tracks and that travel on our route was restricted. He couldn’t say when we would be able to continue.The train doors opened and we walked along the track.

After about half an hour we were finally able to continue our journey. The train moved very slowly and we arrived in Bonn almost an hour late.

Once we reached our youth hostel, we immediately had dinner and started socializing with other participants.

Tuesday, July 15 (Zsófia)

We had breakfast in our assigned meal groups today as well, so we woke up at 7 to eat and were transferred to the contest venue for the practise contest at 8.50. The contest venue was at a huge Telekom building. After having familiarized ourselves with the contest environment, we headed over to Uni Bonn to have lunch. Afterwards, we all gathered in front of a building to take photos of all the contestants together. A while later, we grouped into our assigned teams (which were at the back of our badges). Following, some workshops took place. All the workshops were different, one (mine) was training our AI twin based on how we responded to some questions. After that, we headed over to the venue where the opening ceremony was held. There, we listened to interviews held with women in tech and heard speeches of the organizers. Of course, at the end, all the countries’ and contestants got introduced. After dinner, HPI organized a get together, where we played Bingo (similar to the SOI icebreaker one), had a rock-paper-scissor tournament (which Myriam won), and played another SOI icebreaker, where we had to write facts about ourselves on a piece of paper, receive someone else’s paper, and find the other person. When all of this was done, we (those who didn’t play games) went almost straight to bed to be ready for the contest tomorrow.

Wednesday, July 16 (Laetitia)

We had to get up a little earlier on Wednesday as we had our first five-hour contest in the morning. The contest took place at Deutsche Telekom. Alongside Jane Street, they were one of the main sponsors of the EGOI.

The contest lasted until two o’clock. Afterwards, we wanted to catch up with the leaders, whom we hadn’t seen since the previous evening, but the Telekom staff quickly sent us to the canteen, because they wanted to close it.

After lunch, the appeals session took place. Since no one from our team had anything to appeal, we went straight back to the hostel.

Before lunch, there was a Knoledgde Fair. Everyone was randomly assigned to a group. Seraina and I were placed in the University of Bonn group. In our workshop, two former female students spoke about their lives and explained why it is important to have women in IT. The content of this discussion was very similar to what we had already heard during the opening ceremony and the previous day’s workshop at the University of Bonn. As a result, most of our group was bored. The two speakers did not know what EGOI was. They asked us if we had any programming experience and explained what runtime is.

After dinner, there was a second Knowledge Fair for those who were interested, but we decided instead to play games with other participants.

Thursday, July 17 (Laetitia)

After breakfast, we all took buses to the Telekom headquarters. After an introduction in the entrance hall, we were divided into different groups. I was assigned to the web design group.

In the first part of the workshop, we explored the challenges a person in a wheelchair might face when flying on vacation, from booking the flight to boarding the plane. We then tried to find solutions to some of these problems. After lunch, we had a guided tour of the Telekom building. First, we visited at a small gym and several kitchens. Then we went outside to play table tennis and basketball.

After the tour, there was another discussion about the importance of women in IT. After a final short speech in the entrance hall, we all headed back to the youth hostel.

After dinner, the Jane Street hub event took place. There were various logic puzzles to solve, as well as a nearly all-black puzzle. There were also tables, where you could make bracelets. We didn’t stay up too late as we had our second contest the next day.

Friday, July 18 (Myriam)

Friday was the second contest day, and we had breakfast at 6:45, so we never had breakfast first during a contest day, what a great way to start the day! After the breakfast, we went to the contest room. What is the first thing every SOI contestant does in front of the contest room? Of course Nandor’s motivational speech! The Slovak team joined us, but not the Germans because they were already in the contest room doing yoga while waiting. Then we went into the contest room, where we figured out that we had still more than half an hour before the beginning of the contest, so after talking a bit, we decided to walk around the hall (we had time to do it multiple times before we had to go to our desks). Then, someone from Deutsche Telekom made a speech (the first one of the week that wasn’t about how important it is to have women in computer sciences!), what’s the point ten minutes before the contest? Then the contest started. In the first task, we had some circle with strings and you want to move them in a way there are parallel (don’t worry, this is ABSOLUTELY NOT a geo task, but the implementation was still a bit annoying). In the second task, we had a directed graph, we start at a point and we want to escape the graph by going to node n-1, but there’s a troll who can once change the direction of all the edges, and move the exit from n-1 to 0 and you want to know the length of the shortest path for each starting node, if the troll plays optimally in order that it takes you time but don’t worry, you don’t lose your suitcase in the process (although I still have no clue if the solution is a bit similar or not at all). In the third task, we had the secret numbers of point for each IMO participant per task, and we had to determine how many we had to reveal in order for the ranking to be uniquely decided. But we didn’t have six tasks, but up to 100, not seven points by task, but up to 100, and not 630 contestants, but up to 20’000! What a scam! The fourth task was an interactive one (why two in the same competition???) where you had a tree and you want to make your partner remove the leaves one by one until there’s only one node left, and you can communicate a string of bits. For the full score, you could only use one bit! (But you could use less as well (so zero), so finally three possibilities, but still, how???) After the contest, I learned that I was the last  gold, by one point! I realized that appeals session didn’t already start, and it was so stressing! Seraina, who was nine points below the bronze cut off the first day also caught up and she got bronze! (And she didn’t have to fear appeals at all, she was way above the cut off!) After lunch, there was appeals, so we went back in the contest hall, some of us looked at our code and some others just took our stuff (for me mostly rubber ducks) and left the contest room. After the end of appeals, we went back to the youth hostel, and Seraina, Laetitia, Zsófia and me went to the Jane Street Hub, where we did bracelets, puzzles, jigsaw puzzles, … During the Jane Street Hub, Priska sent me a message to tell me that there wasn’t any appeal, but the cut off partially depended of which countries counted as European too. After that, we went to dinner and then we came back to the Jane Street Hub. After that, we went to the cultural exchange where we brought chocolate (the last six Toblerone and some chocolate bars). We got sweets, pins, fans, pens, key chain, … and we socialized without directly using the chocolate, DO NOT TELL PRISKA!

Saturday, July 19 (Seraina)

Similar to the previous days, we got up at 6.45 and made it to breakfast almost on time. After packing our lunches, we took the bus to a small town called Königswinter, where we realised that we got assigned to a group that took the train to the castle. Laetitia and I were not happy, since we wanted to walk up there. It seemed like the groups had been assigned randomly, as quite a few participants wanted to be in the opposite group. But that was good for us, because now we could switch groups. After a hike / short walk (depending on who you ask) we made it to the top and could enjoy the view. We went to buy some souvenirs and of course played a few rounds of Tichu. Myriam was not happy with our strategy, but we thought it was just fine. We made a short stop at another castle and then went back down. At the River Rhine, we ate our lunches and Zsófia drank her somewhat warm water, before the boat arrived, where we played some more Tichu. Buses brought us back to the youth hostel, we took a shower and changed. Quote from Zsófia while I was stressing about my hair: “We are at an Informatics Olympiad event. People are not gonna look at your hair, they will only look at your medal.” Then it was already time for the closing ceremony. Laetitia and I got our red polo shirts there and I was relieved to see that it actually fits. We heard some more speeches on why women belong in tech and saw a (according to Myriam) strange video, that was produced by AI. Myriam and I got our medals and we took a lot of team pictures, as well as some with other delegations afterwards. Dinner was quite good and after some socialising (this time even without chocolate) and more pictures, most of us went back to the Youth hostel. Sadly, Laetitia already had to leave us. At the hostel, we were happy to discover that there was actually a party happening. We did karaoke (“Unstoppable” by Sia might have been played multiple times) and stayed up way too late. At 3 a.m., Myriam and I decided that it was the right time to pack our bags, but we were too tired for our planned walk in the middle of the night. Then, we finally went to bed.

Sunday, July 20 (Myriam)

On Sunday, our bus to the train station was leaving at 8 am, so we decided to wake up at 7 am with a big lack of sleep (but we still slept), we went to breakfast, and we were ready around 8 am to go downstairs, but we still arrived to the bus before Priska, Leo and Jasmin, so we weren’t the lasts! When we arrived at the train station, we bought some sandwiches for lunch, and then we went to the platform, where Benjamin already was. After a few minutes, Priska’s train arrived (she wasn’t going back to Switzerland with us) and we didn’t realize immediately that it was there so Priska had to run, and I can only tell you that we didn’t see her on the platform after the train left. Our train was 20-30 minutes late it was in Germany, so it was on time but it was a direct train to Basel so we didn’t have any connection trouble, and because it was an SBB train we could even enter in Switzerland and we haven’t been stuck in Basel Germany [1]. In the train, we wrote postcards, chose pictures for the blogpost, and, most important, played Tichu! Then we arrived in Basel SBB and everyone went to take his own train, I think there finally wasn’t any group going together to Zurich.