France TST 2003 D2 Q2
Source:
March 2, 2013
combinatorics unsolvedcombinatorics
Problem Statement
cities are connected by one-way air routes in a way so that each city can be reached from any other by several connected flights. Let be the smallest number of flights needed for a tourist to visit every city and return to the starting city. Clearly depends on the flight schedule. Find the largest and the corresponding flight schedule.