8. Constraints Search, Domain Reduction
PATRICK WINSTON: It's too bad, in a way, that we can't paint everything black, because this map coloring problem sure would be a lot easier. So I don't know what we're going to do about that. How long is this going to take? Here's what we're going to do. We're going to wait till either all the laptops are closed, or this program terminates, whichever comes first. So how long is this going to take? I actually don't know. I think it'll take more than the life time of the universe, but I'm not sure. So let's take a look at a slightly easier map coloring problem. We'll stop this one and change the map to something I call [? simplicia. ?] There's 26 states, one for each letter in the alphabet. And what we're going to do is we're going to do a depth first search for a suitable coloring of this map. We're going to go in order, A, B, C, D, E. And as I've suggested here, at each level we're going to rotate the...