Einstein's Puzzle Thorough Walkthrough (Spoilers)- Pt1

This is the walkthrough for Einstein's Puzzle. If you haven't read the original puzzle/question, you should go ahead and click on the link below. Below will be the explanation of the method I utilized to solve the puzzle. If you want to avoid spoilers you should view the original question before reading below.

You can find the Puzzle here.

Skip here if you want a spoiler-free answer check

Walkthrough:

So this is simple logic puzzle with no real tricks or second guesses. So all you really need is organization to solve this puzzle. I'll be breaking this walkthrough into parts, so you can try it on your own after reading an article:

Here's how I solved it.

All the possible pets.

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Here is the question, for reference:

1. The Brit lives in the red house
2. The Swede keeps dogs as pets
3. The Dane drinks tea
4. The green house is on the immediate left of the white house as you stare at the front of the 5 houses
5. The green house owner drinks coffee
6. The person who smokes Pall Mall raises birds
7. The owner of the yellow house smokes Dunhill
8. The man who lives in the house in the center 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 one who smokes Dunhill
12. The owner who smokes Bluemaster drinks juice
13. The German smokes Prince
14. The Norwegian lives next to the blue house
15. The man who smokes Blend has a neighbor who drinks water

Main Question: Who owns the fish?

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Listing the Possibilities

What I did first was make a list of things we needed to keep track of, as well as all the possibilities within each group (they are all mentioned in the clues):

• Nationalities: 
• Brit 
• Swede 
• Norwegian
• Dane
• German
• Drinks: 
• Tea 
• Milk 
• Water 
• Juice 
• Coffee
• Pet: 
• Dogs
• Birds 
• Fish 
• Cat
• Horses
• Smokes: 
• Pall Mall 
• Dunhill 
• Blends 
• Bluemaster 
• Prince
• House Color: 
• Red 
• Green
• Yellow 
• Blue 
• White
• House Number: 
• #1 
• #2 
• #3 
• #4 
• #5

This list will be important for deduction. 

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Categorizing the Clues

Once I finished making a list of all possible choices, I began to arrange the clues into groups depending on the type of information they gave. 

I noticed there were a few types of clues:

1. The first type would give a direct "link" between two components. For instance, the first clue says "The Brit lives in the Red House". Since everything is unique (only one house color per one person, and no duplicates, and same for the rest of the categories), we understand that "Brit" and "Red House" are linked. And that anything that happens to Red house will happen to the Brit.
2. The second type of clue gives "Unlinked clues" that deal with house positioning. For instance, the tenth clue says that the Blends smoker lives next to the Cat Owner. We can't immediately link any two components together, but we can utilize this when we have more information about house placement.
• The third type of clue comes from the second type of clue. Again, if we look at the tenth clue, we see that the Blends smoker lives next to the cat owner; as such, we note that the Blends smoker can't be the cat owner.

So here is my three categories of clues:

          Direct Link:

1. Brit * Red House
2. Swede * Dogs
3. Dane * Tea
4. Green * Coffee
5. Pall Mall * Birds
6. Yellow * Dunhill
7. #3 * Milk
8. Norwegian * #1
9. Bluemaster * Juice
10. German * Prince
    
    Unlinked:
11. Green (L) White
12. Blends (N) Cats
13. Horse (N) Dunhill
14. Norwegian (N) Blue
15. Blends (N) Water
    
    Negative Link:
16. Green ~ White
17. Blends ~ Cats
18. Horse ~ Dunhill
19. Norwegian ~ Blue
20. Blends ~ Water

Key:
*  = linked

(L) = is left of

(N) = is next to
~ = Is not linked to

The reason I do this is to make referencing and understanding the clues much faster and more efficient. I refer to each of these clues by #. For instance the link between house #3 and Milk is Clue 7.
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Here's your chance to go and try to solve it for yourself. However, If you're eager to see how it is solved, continue onto part 2!

Or double-check (spoiler-free), here