People exchange places
Source: Tuymaada 2023 Junior P7
July 7, 2023
combinatoricsTuymaada
Problem Statement
people forming families of a mother, a father and a child, stand in a circle. Every two neighbours can exchange places except the case when a parent exchanges places with his/her child (this is forbidden). For what is it possible to obtain every arrangement of those people by such
exchanges? The arrangements differing by a circular shift are considered distinct.