Paths of fixed length in complete directed graph
Source: China Mathematical Olympiad 2016 Q6
December 17, 2015
combinatorics
Problem Statement
Let be a complete directed graph with vertices such that for any two vertices one can find a directed path from to . a) Show that for any such , one can find a such that for any two vertices one can find a directed path of length from to (Vertices can be repeated in the path)b) For any graph with the properties above, define to be smallest possible as defined in part a). Find the minimim value of over all such possible 's.