# The winners of SINTEF’s Christmas Quiz

Thank you to all the participants for joining SINTEF as we warmed up for the International Mathematics Olympiad with a Christmas Quiz out of the ordinary. The winners of one ticket each to “Meet the Masters”, an event that is part of The International Mathematical Olympiad IMO 2022, are:

The winners have been contacted directly.

“Meet the Masters” is an event where a collection of cultural personalities, business leaders and top athletes who will share their stories about how they got where they are today and what we can learn from them.

The International Mathematical Olympiad IMO 2022 will be held in Oslo in July this summer.

### 4 comments on “The winners of SINTEF’s Christmas Quiz”

1. Eivind Fonn

If anyone else is stuck on Dec 16, like me, I believe edge recipes do not count as boundary recipes and shouldn’t be in the output. Only corner recipes are boundary recipes.

2. Milan

Hi Eivind. Thanks for interest in solving the puzzles:)

This is correct; A recipe that is colinear to two boundary recipes should not be part of the output.

3. What was the intended solution for the last day? I assumed that the input was randomly distributed, and that the furthest distance to the closest points would not be that big. Based on those assumptions, I splitted the space into 2000 x 2000 x 2000 blocks, and for each block remembered the points in that block. Then only some neighbouring blocks have to be tested for finding the closest points.

• Milan

Hi Jeroen. Sorry for the late reply.
The intended solution for the last day was a non-linear partitioning of space. The partitioning can be done recursively so that each partition contains roughly the same number of points. Implementing an octree in other words:)
However, the solution you are suggesting seems to have done the job. A linear partitioning was enough to deal with instances that we used for testing.
Congratulation for scoring every single point this year:)
Hope to see you again year!