1. On a street there are five houses, painted five different colors.
2. In each house lives a person of a different nationality.
3. These five homeowners each drink a different kind of beverage, smoke a
different brand of cigar and have a different pet.
The question? Who owns the fish?
1. The Brit lives in a red house.
2. The Swede keeps dogs as pets.
3. The Dane drinks tea.
4. The Green house is on the left of the White house.
5. The owner of the Green house drinks coffee.
6. The person who smokes Pall Mall rears birds.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the centre house drinks milk.
9. The Norwegian lives in the first house.
10. The man who smokes Blends lives next to the one who keeps cats.
11. The man who keeps horses lives next to the man who smokes Dunhill.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
14. The Norwegian lives next to the blue house.
15. The man who smokes Blends has a neighbor who drinks water.
Please don't tell me the answer -- OK? Yeah right. The real beauty of this is the simple truth of it. If I tell you that I know who is the owner of the fish and who it is, it doesn't really spoil it for you -- because you won't believe me. First -- it requires verification against a complex set of rules, and second -- knowing that won't even come close to helping find the solution. Finding the solution allows for some assumptions, so there are several different matrices that arrive at the conclusion which -- once discovered will just mean you write in the word fish.
What is a more interesting question to me is how to solve it. Any sort of brute force algorithm seems out of the question. Trail and error combined with intuition and and logic was very fruitful. I expected this to be harder to solve. Stochastic hillclimbing could be an interesting way to solve this. I wonder if I can figure out what that means exactly.