Putnam 2008 A2
Source:
December 8, 2008
Putnamlinear algebramatrixcollege contests
Problem Statement
Alan and Barbara play a game in which they take turns filling entries of an initially empty array. Alan plays first. At each turn, a player chooses a real number and places it in a vacant entry. The game ends when all entries are filled. Alan wins if the determinant of the resulting matrix is nonzero; Barbara wins if it is zero. Which player has a winning strategy?