Dividing into cliques and independent sets
Source: Japan Olympiad Finals 2014 #3
May 17, 2014
inductionceiling functioninequalitiesalgorithmcombinatorics proposedcombinatorics
Problem Statement
In a school, there are students and some of them are friends each other. (Friendship is mutual.) Define the minimum value which satisfies the following conditions:
(1) We can divide students into teams such that two students in the same team are always friends.
(2) We can divide students into teams such that two students in the same team are never friends.
Find the maximum value of in terms of .