China Mathematical Olympiad 1987 problem3
Source: China Mathematical Olympiad 1987 problem3
January 7, 2014
combinatorics unsolvedcombinatorics
Problem Statement
Some players participate in a competition. Suppose that each player plays one game against every other player and there is no draw game in the competition. Player is regarded as an excellent player if the following condition is satisfied: for any other player , either beats or there exists another player such that beats and beats . It is known that there is only one excellent player in the end, prove that this player beats all other players.