Hi everyone,
I'm trying to solve this problem, but I have no idea to begin<http://discuss.codechef.com/questions/5069/tree-again#>. I really need some hints for it: - Given a tree of N nodes, and Q queries. (1 <= N, Q <= 100,000) - Each query has 2 arbitrary nodes on that tree (let's call them A and B). - We define that the distance from another node (let's say C) to A and B is the minimum of {the distance from C to A, the distance from C to B}. - To answer each query, find C so that the distance from C to A and B are as large as possible. I don't think it's possible to do do each query in O(N). It should be O(lgN). Please help me! Thanks a lot in advance! --
