winning strategy with residue classes modulo n
Source: 2019 Austrian Federal Competition For Advanced Students, Part 1 p3
March 4, 2020
number theorygamewinning strategycombinatoricsgame strategyAustria
Problem Statement
Let be an integer. Ariane and Bérénice play a game on the number of the residue classes modulo . At the beginning there is the residue class on each piece of paper. It is the turn of the player whose turn it is to replace the current residue class with either or by . The two players take turns, with Ariane starting.
Ariane wins if the residue class is reached during the game. Bérénice wins if she can prevent that permanently.
Depending on , determine which of the two has a winning strategy.