MathDB
Gangnam-Style

Source: Junior Olympiad of Malaysia 2013 P4

July 20, 2015
combinatoricsgames

Problem Statement

Let nn be a positive integer. A \emph{pseudo-Gangnam Style} is a dance competition between players AA and BB. At time 00, both players face to the north. For every k1k\ge 1, at time 2k12k-1, player AA can either choose to stay stationary, or turn 9090^{\circ} clockwise, and player BB is forced to follow him; at time 2k2k, player BB can either choose to stay stationary, or turn 9090^{\circ} clockwise, and player AA is forced to follow him.
After time nn, the music stops and the competition is over. If the final position of both players is north or east, AA wins. If the final position of both players is south or west, BB wins. Determine who has a winning strategy when:
(a) n=20132012n=2013^{2012}
(b) n=20132013n=2013^{2013}