IOI Competition Day 2

Today was the second day of competition and it's now all over. Now there's the anxious wait till the awards ceremony on Tuesday evening, with an excursion to the Plitvice Lakes tomorrow, which I've heard is going to be amazing.

Quick catch-up on the events since my last post. On Friday night we discovered that the room next door was not empty as we had originally thought. Rob Kolstad was in it. He stuffed up with his flights and booked to arrive a day late. Anyway, he's one of those people that just knows how to talk, and talk. Between Rob and Donald our early night turned into a late night, 3 hours of chatting about life stories later. It was enjoyable though.

Yesterday we had an excursion to the Jarun Lake. It was a nice break from the usual environment and although it was overcast when we arrived, the sun came out later on which made things rather pleasant. There wasn't much to actually do there besides relax and chat with the other teams, but it was great. Now's a good time to mention just how much they try feeding us. We had brunch at the lake, which followed an early breakfast. Then when we returned, we still had lunch and then dinner later on! And it's all fairly decent for such an event.

One of the New Zealand contestants borrowing Charles' juggling balls at the lake:


After lunch we took another tour of the city. Unfortunately the shops closed at 15:30, so we didn't have much shopping time. However, we had a wonderful time seeing more of the city. One thing I really love about most European cities is the rich history. Zagreb's not excluded by any means!


After the tour of the city, it was time to wish the team good luck and go over to the GA meeting to go through the second and final problem set. This time I had Brian Deen from America sitting next to me and we went through the problems together. Miners was an easy DP. Pairs requires a 3D range tree, which can be compressed into a 2D range tree. Quad trees should also work for most test cases. Training was a very nasty graph theory problem involving even cycles. The problems, test data and official solutions have been released here.

There weren't any major concerns with the problems, except that it was requested the them of Pairs change from what it was initially. The English was a little poorer for this second set of problems, but it was dealt with well and much more efficiently than the first round. The atmosphere was as good as always. We were out of the translation room by 23:00.


The next morning when we went for breakfast, we were pleased to find that the quarantine issues from before had been ironed out and there was no repeat this time. While the contestants wrote the second round, we once completed the second half of the IOI Conference. Once again, some very interesting talks by some countries which we will have to analyse in more detail and learn from their experiences.

After the conference we waited for the team to return. The initial look on their faces wasn't that excited, but they thought they had faired reasonably well. Some ended up pleasantly surprised with their scores, while others a bit disappointed. For all but one of them this is their last IOI. After lunch the scores were waiting for us, which was very impressive. We got 2 triple digit scores and two double digits. I'll let out the real scores after the awards ceremony on Tuesday. Bruce back home on the online contest has impressed once again though. He got the max!! That's all their is to say really.

We had a meeting with Rob after the analysis phase on the possibility of creating a team event for the future, but I'll leave the details to a later post. There was also a very long GA meeting during which lots happened, but details in later post. Just one thing worth noting is some statistics on mark distribution per problem:


Aliens: 50 full scores
Flood: 24 full scores
Sails: 12 full scores
Miners: 131 full scores
Pairs: 9 full scores
Training: 3 full scores

So, watch out for more on those two meetings and our trip to the lakes tomorrow!