Tennis Club hosts a series of doubles matches
Source: Chinese Mathematical Olympiad 2000 Problem 3
August 19, 2013
combinatorics unsolvedcombinatorics
Problem Statement
A table tennis club hosts a series of doubles matches following several rules:
(i) each player belongs to two pairs at most;
(ii) every two distinct pairs play one game against each other at most;
(iii) players in the same pair do not play against each other when they pair with others respectively.
Every player plays a certain number of games in this series. All these distinct numbers make up a set called the “set of games”. Consider a set of positive integers such that every element in is divisible by . Determine the minimum number of players needed to participate in this series so that a schedule for which the corresponding set of games is equal to set exists.