Board Thread:Contests and Competitions/@comment-25825221-20150811213926/@comment-24808864-20150812044400

OK, thought about it. Very cool problem. I am almost there. I can figure out one machine for sure, but need to think about how to distinguish between the "other" two machines. You should understand with the explanation below:

First question: Are you the 0 machine?

Second question: Are you the 0 machine?

Third question: Are you the 0 machine?

The zero machine will answer "colour 1, colour 1, colour 1"

The -1 machine will answer "???, colour 2, colour 2"

The +1 machine will answer "colour 2, colour 2, ???"

The only issue left that I have to think about is how to distinguish between the -1 and +1 machine in the case that both question marks are "colour 2."