Putnam 2014 B5
Source:
December 8, 2014
Putnamabstract algebragroup theorycollege contestsPutnam 2014Putnam matrices
Problem Statement
In the 75th Annual Putnam Games, participants compete at mathematical games. Patniss and Keeta play a game in which they take turns choosing an element from the group of invertible matrices with entries in the field of integers modulo where is a fixed positive integer and is a fixed prime number. The rules of the game are:(1) A player cannot choose an element that has been chosen by either player on any previous turn.(2) A player can only choose an element that commutes with all previously chosen elements.(3) A player who cannot choose an element on his/her turn loses the game.Patniss takes the first turn. Which player has a winning strategy?