MathDB
A nice way to color the square board

Source: Southern Summer School, gr. 10

July 9, 2017
combinatoricsminimizesquare grid

Problem Statement

In a square board of size 1001 x 1001, we color some mm cells in such a way that: i. Of any two cells that share an edge, at least one is colored. ii. Of any 6 consecutive cells in a column or a row, at least 2 consecutive ones are colored. Determine the smallest possible value of mm.