Hi Codeforces,

As I mentioned before, as part of my Master's thesis, besides my book I am organizing a contest with exclusively geometry problems to showcase some types of problems or techniques that I think could be cool to see in the future in ICPC and other contests.

It will take place this Sunday 08:00 UTC in the Gym (the link will be http://mirror.codeforces.com/gym/101793, registration should open 6h before and remain open during the contest). There will be 4 problems to solve in 3 hours.

The problem should be particularly relevant for students participating to the ICPC. But the problems will be *very hard*, so I think they can be interesting to everyone with a sufficient level in geometry.

The problems will be roughly sorted by estimated difficulty, but please read all the problems, as you might find that you feel more interested by one of the "harder" problems. The statements will be given all together in a PDF attachment. The samples will be in the PDF as well as on the problem pages.

Since it's my first time organizing a whole contest by myself, I hope everything will go smoothly. I would like to thank yunoac for the precious feedback on the tasks (and of course his amazing support during my whole thesis), Nicolas16 for beta-testing the problems in a tight schedule, and of course MikeMirzayanov for the great Codeforces and Polygon platforms.

I hope many of you will participate to the contest and enjoy the problems. See you for the editorial!

PS: You might want to revise your 3D geometry. ;)

**UPD:** The length is confirmed to be 3 hours. The contest will be held under ICPC rules. You can participate either individually or in a team.

**UPD2:**

Congratulations to the winners:

who also happen to be the only participants to solve at least one problem.

Thanks to everyone for participating, the editorial is coming in a moment!

I am not sure it is the right place for the comment, Still trying. In the problem http://mirror.codeforces.com/contest/975/problem/D there is a lot of redundant data: coordinates of points and also coefficient b in the straight line. Is it OK for a problem? Is it on purpose to make life harder? Or just by mistake? Thanks, Levi My solution has been accepted here.

I think it is ok. It is used to confuse you in the problem . You may think usr some math methods at first.

Auto comment: topic has been updated by vlecomte (previous revision, new revision, compare).Auto comment: topic has been updated by vlecomte (previous revision, new revision, compare).Where can I find problems?

http://mirror.codeforces.com/gym/101793/attachments/download/6993/statements-en.pdf

How to solve the problems?

Editorial here!

Thank you