MathDB
JBMO Shortlist 2021 C6

Source: JBMO Shortlist 2021

July 2, 2022
JuniorBalkanshortlist2021combinatoricsgameboard coloring

Problem Statement

Given an m×nm \times n table consisting of mnmn unit cells. Alice and Bob play the following game: Alice goes first and the one who moves colors one of the empty cells with one of the given three colors. Alice wins if there is a figure, such as the ones below, having three different colors. Otherwise Bob is the winner. Determine the winner for all cases of mm and nn where m,n3m, n \ge 3.
Proposed by Toghrul Abbasov, Azerbaijan