MathDB
flights, rootes and two mins

Source: JBMO Shortlist 2014 C2

April 24, 2019
combinatoricsminimum valueminimum

Problem Statement

In a country with nn towns, all the direct flights are of double destinations (back and forth). There are r>2014r>2014 rootes between different pairs of towns, that include no more than one intermediate stop (direction of each root matters). Find the minimum possible value of nn and the minimum possible rr for that value of nn.