Polish Combinatorics
Source: Poland - Second Round P2
February 8, 2020
combinatoricscomputer science
Problem Statement
Let be a positive integer. Jadzia has to write all integers from to on a board, and she writes each integer in blue or red color. We say that pair of numbers , where , is if and only if number of blue numbers among is odd. Determine, in terms of , maximal number of good pairs.