Hi there,

Nearest neighbour is a problem where you are given N points and you are asked to process online queries: for a new point find the closest point from given N points. Euclid distance is used:

Who knows where I can test this problem?

Hi there!

Problem from past regional olympiad: There are N ≤ 5000 distinct points |x_i|, |y_i| ≤ 10⁴ on the plane. You are asked to find the number of different right triangles, where the vertices are from N points.

TL: 2s, ML: 64MB

Thanks

Hi everybody!

Recently I have thought of how can I solve such problem: There is a root of a tree. At each step player can create on any leaf of a tree either left child (with probability p) or right child (with probability 1 - p). What is the expected value of a height of a tree after n player steps?

UPD: Leaf is chosen with the same probability (equiprobably).

Leaf -- is a vertex with the number of children less than 2.

Hi everybody!

Will be it possible to participate in IOI 2013 online?

Thanks