MathDB
Tournament with lowest cost

Source: IMO Shortlist 2018 C5

July 17, 2019
combinatoricsTournament graphsIMO Shortlist

Problem Statement

Let kk be a positive integer. The organising commitee of a tennis tournament is to schedule the matches for 2k2k players so that every two players play once, each day exactly one match is played, and each player arrives to the tournament site the day of his first match, and departs the day of his last match. For every day a player is present on the tournament, the committee has to pay 11 coin to the hotel. The organisers want to design the schedule so as to minimise the total cost of all players' stays. Determine this minimum cost.