IOI 2024 Blog (real)

IOI 2024 took place from 1st - 8th of September in Alexandria, Egypt

Charlotte Knierim
News

Sunday, 1.9.2024 (Jovian)

Having skipped the camp for reasons, I was making the trip to Egypt with Luca instead, starting on the evening of August 31.

My IOI got off to a great start as our flight from Zurich to Istanbul landed at half past midnight, nearly two hours behind schedule and about five minutes after the gate to our connecting flight (to Alexandria) closed. We tried to see if by some chance the gate agents would let us in all the same, trying to run across the airport (by the way, big thanks to the airport employee who, upon being asked by Luca if we could make it on the flight, responded “hurry up” pointing in the general direction of the gate, thoroughly tiring us for no reason), but clearly there was no chance as we found ourselves in front of a security check. As a result, Turkish Airlines booked us onto the next flight to Alexandria leaving us stranded in Istanbul Airport for five hours. Seemingly, delays were a very common issue here, as was made no secret by the abundance of transfer desks and the long lines of people waiting at them.

We got meal vouchers and proceeded to get scammed (as it turns out, meal vouchers only allow you access to one of a small pre-selected set of menus, resulting in one of the worst Subway sandwiches I’ve ever eaten). We met the Algerian team (or 75% of it, anyway), who had fallen victim to a very similar delay and subsequent miss of a connecting flight (to Cairo rather than Alexandria, for whatever reason). We went to a “NapZone” and tried our luck at 1.5 hours of sleep, instead getting 5 minutes. We probably walked the entire length of the airport terminal at least three times in each direction, and met a bunch of delegations (seemingly also having faced the reliability of Turkish Airlines) before finally boarding our flight to Alexandria.

At 9am, we arrived and were promptly greeted by the 100dB airport officer you might remember from earlier. Then we got on the bus and finally arrived at AASTMT at half past eleven. Our team’s guide was there to greet me, and he took me to our team’s hotel. I knocked at the room’s door, Elias opened it, and the Swiss team’s cardinality was increased to four. But only for a moment, as my guide called me downstairs to get my luggage, for which I waited another hour (at least I got a nice chat with some of the guides). By the time all was done, it was 1PM and so we went for registration (and obtained our very cool team T-shirts [thanks Ursus {he designed them}]). Next, our guide gave us a tour of the campus, showing us its sports fields, various buildings, and a cool gym that apparently was mostly used for its air-conditioning. We then proceeded to the restaurant for lunch, which was slightly better than what other universities had offered to me in the past.

The rest of the day was relatively uneventful as most of us either wrote blogposts (it’s hard work; just read the absolute masterpieces above) or caught up on much needed sleep (I had gotten a grand total of 30, maybe 35, minutes of sleep in the past day). We briefly left for dinner and bought some snacks then headed back.

Monday, 2.9.2024 (Jovian)

This was a day of two parts: the practice contest in the morning and the opening ceremony in the afternoon.

Breakfast was scheduled for 6-8am. Our guide strongly urged us to arrive at 6, as we apparently had to be at the contest hall at 8 (“Please guys don’t be lateeee”); instead we woke up at 7:30 and arrived at the breakfast hall at 8. No breakfast for us? Actually we did get breakfast; in fact there was a huge queue of teams standing outside the restaurant with everyone seemingly having done the same as us. See? Even in times like these, we’re always punctual. We proceeded to the contest hall: a huge tent housing over 350 (I think?) contestants, obviously with lots of air-conditioning. The practice problems had been published prior to the contest, so we spent most of the time testing the grader features and the machine, making sure that we were completely familiar with them before the contest.

Afterwards it was time for lunch. Except that it was also time to head to the opening ceremony as well, so the two were to be combined together. Unfortunately Ursus was still feeling a bit sick so he went back to the hotel (glad to hear he’s getting much better), but the rest of us headed onto the bus (after a good bit of waiting) and got boxes of lunch containing interesting chicken sandwiches. The vegetarians obviously got something different (after a good bit of waiting), then our bus departed (after a good bit of waiting). (You may sense a recurring pattern here.)

Soon we arrived at the Bibliotheca Alexandrina, where they would hold both the opening ceremony and a tour of the library. The opening ceremony was held in a grand, spectacular hall, and consisted mostly of the usual, although a significant portion of the speeches (possibly over 50%) was delivered in Arabic. We were also given motivational words by the great philosopher and pop star Kylie Minogue. The delegations were announced in a completely politically neutral way, and when Switzerland was called, we threw chocolate at the crowd as we always do. We stole the Swedish flag (but were forced to give it back for reasons of politeness) and- Emmmm, sorry to interrupt this blog post… Actually, I’m as sorry about it as about the reason I have to write this.

After the Opening Ceremony, we got the sadge[sic!] news that we were not going to visit the library. This made us very sad. Then, Elias saw some stones downstairs. It looked so cool [1] that I (Yaël [2] ) and Elias decided to do our own little clandestine tour. So we took the stairs first and had the conversation

Are you guests?

—Some random person

Yes yes

—Us

There was nothing to see there, so we took the lift to the second floor. By giving off the impression that we obviously did belong there [3] , we managed to look at more stones in various forms, and also at some glass statues. There were also some pictures of some probably important people. Then we went down again, having not found any books, but ach why should a library need any. We found our guide outside, who asked us where we had been. I said the toilet, Elias said looking around. He wasn’t that happy about my answer, but we managed to make it sound all normal in the end (or almost).

Ok, you can have it back now. We were boarded onto buses and sent back to AASTMT, and had dinner before slowly returning to the hotel to get sleep (a foreign concept) ahead of the important contest.

[1]Not really, but we need a reason
[2]Didn’t the excessive use of footnotes and other stuff tell you that already?
[3]Who doesn’t wear T-shirts with IOI 24 kangaroos and ducks on them?

Contest Day 1, Tuesday 03.09.2024 (Ursus)

Huh, what do I hear? Is it:

  1. URRRRRRRSUS
  2. Gomorrow!
  3. Ej, come into sauna!!
  4. Umta-umta-umtata

The answer is: Gomorrow!

This - ladies and gentlemen - was the alarm of one of your biggest days in our lives, All we trained for, was for this Tuesday and next Thursday.

But well, we planned everything and got some good night sleep so that we get up at 7:20 eat breakfast and be at the tent at 8:00. Then our guide phoned me (literally after waking up) and said breakfast would only be until 7:30 because of changes (which I haven’t heard of obviously). Well okay, it seems he wrote that to us yesterday at midnight [4] so it was our fault.

Today I was feeling almost back to normal (interpreting from the observations, it may actually have been the stress and low sleep I had in recent days [5]). Thank you for all the leaders, Elias, Jovian and Yaël and the guide for taking care of me during that time.

But anyway, our big contest awaited! We grabbed some food (in a fast manner) and headed straight to the contest hall. There we just had to wait for around 20 minutes in the scorching heat, so why shouldn’t we have done the Nandor-motivational-speech (Luckily, this one wasn’t interrupted unlike in some other competition). After we finally got inside, we still had to wait for around half an hour until the contest started. But when the time had come, we knew, this is our moment:

Elias First read the tasks and yeah, this problem looks easy… Let’s implement a lazy segtree.
Jovian Interesting problems I guess. But they’re all kind of stressful.
Ursus Uff, these tasks are certainly something else. Let’s try to get “easy” subtasks.
Yaël Nö (continues to fail the rest of the contest) [6]

The contest has ended, and we discussed points and important things. We talked (ate Lunch (which still wasn’t salted (or had any other spice))) and it seemed that the second task was a very interesting discussion subject.

Anyway, to avoid spoilers I’ll leave out the details of this very pleasant conversation, I quickly left to the hotel and did some blog stuff, some hobby stuff and some news stuff, until I wanted to visit that mysterious Jane Street Hub. It was in the room where the registration was, and there were allegedly a lot of board games. In reality, most people seemed to play poker, others actually played real games. Others solved some puzzles and I also cracked one with some of the Swedish people (We were dominating it, YEAH!). Ah yeah, Harry and Theodor solved some pure blue puzzle and Joshua came after they finished it and obviously all three received prices for solving it. They gave me the prices since they had duplicates. That’s cool, I guess.

Whatever, there wasn’t really a game I was interested in or already had enough players, so I quickly went back to the room (with a little detour to the popcorn stand). There I researched about some subjects until I went to Dinner with Jovian.

I must say when we met Johannes on the way (who already ate Dinner), and especially when he said, he was never so excited about the food than today, especially for the one cheese, I thought he was simply joking. But holy moly, that Dinner was definitely an experience like nothing else! I tried the cheese and… WOW, I didn’t think something like that is possible! Especially if you just smelled it, this flavor must’ve been the most unforgettable scent in this entire week! Despite not being spiced or anything like that, that really must mean something!

That scent, how would I describe it? It’s literally the same scent as 5-days old and worn socks.

Anyway, if there are fries (and there was) I’m happy. Still, the food urges to be salted. After Dinner, I went to solve another Hard-level Sudoku (Jovian solved one too). Elias came by grabbed the key and went to the hotel. After we solved the Sudoku (and received another fancy Panda) we want back to our roome. At the hotel, the door was locked…

Elias where tf r u? – Ursus

Let us analyze the plot of Find Elias 4™: The waste in time. (2024 SOI u©)

  1. First Elias, Jovian and Ursus were in the room.
  2. Elias went with his backpack out (Ursus was thinking “ach, he’s going to get dinner”).
  3. 10 minutes later, Ursus and Jovian went to get dinner (and closed the door since they’re the last ones).
  4. Elias went back from his walk and felt abandoned.
  5. The rest finished with dinner and went with their interests.
  6. Elias ate dinner and went to Ursus to grab the keys. (Ursus was thinking “ach, he goes back to our room”)
  7. Elias went playing at the Huawei place.
  8. Ursus and Jovian finished with Sudoku, went back to the room.

And that was only the backstory! Ladies and gentlemen, never in our lives had Find Elias™ such an extensive history [7]. What’s the gameplay? We went to the Huawei place and found him… BUT THAT STORY THOUGH! Anyway we all went back together and well, that was our day.

But there’s a universal fact, which goes like this:

LET2L \propto E \cdot T^2

Where LL is the length of the blog post, EE the number of events during that day and TT the amount of free time you got. Therefore, I will set T=0T = 0 and go to bääd to not kill myself.

[4]I’ve heard there was also a message earlier in the IOI Discord, but I didn’t find that.
[5]So pro tip: Never think you’ve slept well after 4 or less hours, even if it feels so.
[6]Note by someone who can now edit blogposts: I didn’t realy listen to the question, I just heard it was about the contest
[7]That’s surely what makes games great… (wait what?)

Wednesday, 4.9.2024 (Elias)

Today was excursion day, beach day. We woke up a little later than usual and went to eat breakfast before getting into the buses. They were supposed to leave the campus at 9:30 but ended up leaving at 9:50 (the bus schedule is still bad). After about a half-hour drive, we got to the beach, which was part of the hotel the guests were staying in, so we met Luca there. From the Swiss team, only Johannes, Luca, and me wanted to go into the water as Jovian had forgotten his bathing suit and both Yael and Ursus were still a bit sick.

In the water, we met up with the Swedish team and played frisbee with them. When I got back from the water, the rest of the team were busy playing cards, an odd game called hanabi, where you can see everyone else’s cards but not your own. Shortly afterwards, Charlotte left us to talk with some other teams. We spent most of the beach trip under our sunshade playing games and relaxing. I left at some point, first to get lunch, then to get some branded towels from one of IOI’s sponsors, a crypto liquidity firm, and finally to go into the water a second time. This time I even saw some small fish. At around two o’clock, we left the beach and took the buses (which were on time for a change) back to the campus.

The rest of the day was mostly more relaxation and going to the Huawei and Jane Street booths. At around ten o’clock, we went to sleep to be well rested for tomorrow’s contest.

Contest Day 2, Thursday 05.09.2024 (Yaël)

"Gumorow, is that a bockenen"

The music that woke us up was not loud enough. But today was contest day, so standing up anyway was still a pretty okay idea. At least I had slept well enough after a horrible night yesterday.

I don’t need to tell you about breakfast, everything about it can be deduced by the blogs of the previous days.

At T1hT - 1h [8] (approximately), we arrived in front of the contest hall and tried to get some shade. We were amazed that we hadn’t got the mandatory

where r u guys?

from our guide yet. It turned out he wasn’t coming to wish us luck or anything similar and we entered the contest hall at T0.5hT - 0.5h. We did a Nandor Motivational Speech in the middle of the hall, but there weren’t enough people yet to look at us weirdly. We did nothing interesting until T0.25hT - 0.25h. At this point, other people started to hop around (not as well as we did for the Nandor Motivational Speech, but acceptable), so we joined. Sadly, we were interrupted by the organizer who said he really appreciated what we were doing, but could we please go back to our seats like the brave little contestants we obviously are. We then had to look at our computers (without touching them!) to simulate us being in the contest for the sake of a video drone which flew back and forth a few times.

Finally, T0hT - 0h arrived. The contest had an interesting string task in the beginning (which is unofficially always the easiest task). I managed to get splendid 3 points on it. Jovian wrote some solution which even the task author is not sure should pass for the subtask it got. Otherwise, it remained a mystery (even for some people who spend 2.5h2.5h on it). The next task was cool [9] and used only prefix sums in its solution, but was still quite difficult to implement without any bugs. For a long time, it looked quite bad, and I wasn’t able to get everything right. The last task used a lot of colors on a graph and was thus very difficult for Ursus. During a toilet break in the last hour of the contest, I finally managed to find yet another bug in my solution for Mosaic (the second task), and this turned out to be the last one [10] ! I was quite happy that finally I had managed to implement something correctly.

After the contest, we finally sow our guide for the first time today, but what was more interesting was what he had on his phone. But the ranking is a story for another day [11] . I will just tell you that Jovian didn’t seem very hyped. Part of the delegation then stayed in front of my computer for another hour and talked about the string problem without understanding any of it.

Hunger then took over, and we went to get lunch, which can also be inferred by the previous posts. We talked about the possibility of creating a random ICPC team at the University of Basel maybe using some loopholes in the eligibility system.

When I got back to our room [12] , Ursus was playing the game which should be forbidden because of too much stuff moving around and light flicking on and off. I tried to learn it, and we played as a duo for some time (on half speed from double speed which he normally plays). I understood that one needs to

  1. Not die (I did this all the time)
  2. Kill monsters (I did not do this all the time)
  3. Do everything to the beat of the song (I did this none of the time)

After this successful interlude, I got back my small contingent of ducks from the contest hall (clearly not enough, otherwise the first day would have been better). I also found out I was 5 minutes away from getting 21 more points.

Because the swedes were going to the gym (way too tiring for everyone apart from Elias) we went to the Jane Street Hub and solved a riddle after first solving “what is this even about?”. I also played some Volleyball with people. During this process, I lost the rest of my delegation.

But at dinner I found some friends [13] at some table (the swedes + island + Irish people). We talked about military service, how to convince the IC that we could participate one more year and cut a plastic bottle with a plastic knife. Afterwards, we also cut a plastic spoon. I don’t want to bore you with the details, but one problem is that the knifes tend to overheat and melt, so you have to get the cutting speed just right.

To finish the day with some “sports and fun activities” [14] we played a round of ultimate on a miniature field. We lost. Then, we were invited to Black Magic with some guides and the Swedish delegation. We had quite some difficulties but managed in the end. It was very fun for the guides. As a great finale, we learned some Arabic dances (with variable success). I just hope nobody will ever find videos on the internet reporting this. I got tired then and went to sleep.

And now a great era ends for me, as this will be my last blog post as a participant. Sadge.

[8]great formatting
[9]The correlation with the fact that I solved it is not a causation relation
[10]I somehow feel that I didn’t manage to create a lot of suspense…
[11]Now it’s better I think, I’m getting good at cliffhangers
[12]Or freezer
[13]Charlottes’ term
[14]as written on the schedule

Closing Ceremony, Friday 06.09.2024 (Ursus)

“Gomorrow” (I know this is technically not spelled correctly, and the Swedish delegation is probably quite disgusted about this way of writing, but…) it’s one of the last days in Egypt.

Today we had a very interesting schedule ahead, I personally was very hyped for the pyramids! But that came with the cost of getting up at 7:20 AM and leaving at 8:10 (on time obviously). This experience is best described with the quote from Elias.

… our timely arrival at the Grand Egyptian Museum. Buses will depart at 8:10. – Information forwarded by our guide

Elias:

image1

Press X to doubt. [15]

Interestingly, the buses arrived at earlier than planned, which was nice! As on the schedule we first visited the “Grand Egyptian Museum”. We already saw the big pyramids in the distance, there was also a nice place inside the museum where we had a nice view on them. The museum by the way was huge (as in dimension) and empty! It could’ve easily been a storage room. We had a little tour in the museum after we had a puzzle hunting. Alas, we were very hungry and we obviously didn’t feel to do puzzle hunting at 14:00, when we haven’t had food before. Elias just bought a Döner and then did the whole puzzle thing on its own, the rest and I were just tagging along, trying to survive somehow. Anyway, “we” solved it and won a bag… I love it. Truly… Finally, we got food, and I was hoping, since it wasn’t at the AASTMT canteen, that it would taste good. Yeah, you could think what was the case with the taste, but we had a nice discussion with 2 Indonesian leaders. One of them was apparently the creator of two IOI tasks this year (nice!), and we discussed old and new IOI problems.

Time flew by, the schedule said that we would’ve had a tour at the pyramids since an hour, but that got cancelled… I would’ve been somewhat pissed if we didn’t go to the pyramids after all, but we luckily we were still transferred to the pyramids, but just to make some nice pictures there. Seeing the pyramids in person was a very cool experience, climbing them would’ve been fun but the guides wouldn’t allow that for some reason. With a lot of group photos, the mandatory duck photos, Yaël tried to steal Sven from the Swedes (they weren’t appreciating that, obviously). Half of the Flickr photos probably are going to be from this, but relatable, pyramids are a miracle.

After that, we had “Dinner at Sphinx” and “Closing Ceremony” afterward on the schedule. But in reality, it was way fancier than I would have ever imagined. We had “Dinner at Sphinx and Closing Ceremony”. A little bus ride later, we had some place with super fancy tables, chairs and food (the food was good this time, for real now [16]). There were 3 screens around (we picked the best spot to see all of them) and they were used for backgrounds in dancing breaks, videos and decoration basically. It was not in a hall, we had the sky above us, and an extremely nice view on the 3 pyramids as well as the sphinx. In addition to all of those, there was a fancy RGB-lightray system and a red carpet through the middle.

image2

I mean, I didn’t expect such a high fanciness-level throughout this entire week, this was awesome!

Obviously, we ate dinner then we had chunks of bronze, silver and gold medalists. Between each of those we had sometimes dance-breaks from the opera-team. They actually had nice dancing sequences (sometimes not), but I’ve found it a bit triggering that the light was synced to the beat and rhythm but was delayed by around 100-300ms.

Back to the medals and the results:

  • Jovian got silver 🎉🔥💪 🥈 💪🔥🎉
  • Elias got bronze 🎉🎉 🥉 💪💀
  • Yaël saved his bronze 🎉🎉 🥉 💪💪
  • Ursus got an honorable mention 👏👏👏

Everyone got something, historically so far, that’s a good performance 🔥! Not everyone got what they had hoped for, but I think everyone is still happy with what they’ve got.

After the fancy medals showoff, we made some team photos and quickly went to the buses.

You would think a bus ride in the middle of the night would be obvious: Sleep, sleep and sleep. Instead, this was an absolut rollercoaster of a 3-hours ride. We, the four participants, went into the backseats so we could sleep. Despite me having difficulties sleeping with a somewhat loud bus acceleration noise, the way the bus was driven, was crazy! At some point, the back of the bus fell or something like that, and we were flying for around a second! Yaël even touched the ceiling, which was clear sign to fasten the seatbelt. Yeah and the rest of the ride was constant acceleration and de-acceleration, you could listen to the motors that it was not a calmly ride.

But after 3 hours, we finally arrived back at AASTMT and obviously, we went to sleep… For a looooong time!

[15]If thou still dost not comprehend: The Buses left at 8:40 and later, a nice difference of half an hour
[16]Okay correction: If you were vegetarian (which we were 3), then you just had the main dish, without the meat. The main dish consisted 50% out of meat. (It looked so stupid when they just got rice without the meat.)