Tournament without 4-cycles
Source: 63 Polish MO 2012 Finals - Problem 4
April 23, 2018
combinatoricsTournament graphsgraph theoryPolandTournament
Problem Statement
players () took part in the tournament. Each player played exactly one match with every other player, there were no draws. There was no four players , such that won with , won with , won with and won with . Determine, depending on , maximum number of trios of players , such that won with , won with and won with .
(Attention: Trios , and are the same trio.)