Wednesday, July 14, 2004

Putnam Problem of the day...

Harvard has a Putnam Exam page that contains (apart from all the Harvard rah-rahing), a "problem of the day". Today's problem:

In Determinant Tic-Tac-Toe, Player 1 enters a 1 in an empty 3x3 matrix. Player 0 counters with a 0 in a vacant position and play continues in turn until the 3x3 matrix is completed with five 1s and four 0s. Player i wins if the determinant is iPlayer 0 wins if the determinant is 0 and Player 1 wins otherwise (thanks, Amit). Assuming optimal strategies from both players, who wins and how ?

What they need is an RSS feed. hmm....


  1. The tic-tac-toe problem is not quite correctly stated. Player 1 wins even if the determinant is -1, for example.

  2. The original problem statement is available here.Problem B-6 from that year is quite beautiful and my favourite from this set. Try it!

    Sorry, forgot to sign the previous post.

    -Amit Chakrabarti


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