draw diagonals in a regular (2n+1)-gon
Source: All-Russian 2007
May 4, 2007
geometrygeometric transformationreflectioncombinatorics unsolvedcombinatorics
Problem Statement
Two players by turns draw diagonals in a regular -gon (). It is forbidden to draw a diagonal, which was already drawn, or intersects an odd number of already drawn diagonals. The player, who has no legal move, loses. Who has a winning strategy?
K. Sukhov