reversing row/column of number table
Source: Yugoslav TST 1997 P3
May 15, 2021
combinatorics
Problem Statement
Numbers are written in the cells of a table. It is allowed to apply the following transformations: exchange places of any two rows or any two columns, or reverse a row or column. (When a row or column is reversed, the first and last entry exchange their positions, so do the second and second last, etc.) Is it possible that, after finitely many such transformations, arbitrary two numbers exchange their positions and no other number changes its position?