Good sets covering a table
Source: 239 MO 2024 S4
May 22, 2024
combinatorics
Problem Statement
Let be a positive integer greater than and let us call an arbitrary set of cells in a square if they are the intersection cells of several rows and several columns, such that none of those cells lie on the main diagonal. What is the minimum number of pairwise disjoint sets required to cover the entire table without the main diagonal?