Comments for TICS

Comment on Solving Einstein’s Riddle using nondeterministic computing by Einstein meets F# part 1 « The Code Nose

Einstein meets F# part 1 « The Code Nose — Tue, 17 May 2011 03:54:31 +0000

[...] found a blog post in my daily barrage of code forum emails that looked interesting enough to try and solve with F#. [...]

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Comment on Solving Einstein’s Riddle using nondeterministic computing by Ernie

Ernie — Thu, 03 Feb 2011 22:13:40 +0000

SOLVED IN 20 MINUTES…

I cheated, I used EXCEL… LOL…
Just put all five of each option in an excel table and knocked them off one-by-one. 20 minutes, and the German had fish for pets.
Was fun and the programming sampler was interesting, too…

Comment on Solving Einstein’s Riddle using nondeterministic computing by rei

rei — Fri, 24 Dec 2010 14:40:40 +0000

Although, to be honest, I’m pretty sure that more than 2% of the population can already solve this problem. I’m not *that* smart…

Comment on Solving Einstein’s Riddle using nondeterministic computing by rei

rei — Fri, 24 Dec 2010 14:36:28 +0000

I did this in Excel with the condition that I wouldn’t erase anything I’d written down — meaning that all the backtracking would have to be done in my head.

That’s probably most fair and realistic given the lack of ctrl+z back in Einstein’s time.

Then part of the challenge is in knowing what kind of logical tricks you need to use, and part of it is in memorizing the variables that you’re trying to deduce. The former can be polished in a course in philosophy or math or anything of the likes, and the latter is probably a matter of cognitive capacity, which challenges like these surely improve.

Given that, I’m certain that more than 2% of the world’s population can be made to solve this riddle with the right education, practice and patience — and that what they gain in the process would be beneficial to practically everything else they do in life.

Comment on Solving Einstein’s Riddle using nondeterministic computing by Ryan

Ryan — Thu, 09 Dec 2010 14:41:41 +0000

I did this on paper in 20 minutes and I am only 15. It seems like quite an easy problem. Most people would be able to get the solution eventually.

Comment on Solving Einstein’s Riddle using nondeterministic computing by I Wonder

I Wonder — Thu, 09 Dec 2010 14:37:35 +0000

[...] wonder if it is possible to solve Einstein’s Riddle using [...]

Comment on Solving Einstein’s Riddle using nondeterministic computing by Pedro Ramos

Pedro Ramos — Thu, 09 Dec 2010 02:02:16 +0000

Hi.
This is just a small VBA code the I wrote, just for fun.
It solves this problem in less than a second, on my PC, at least.
Jus copy-paste to an Excel Module and try it.



Dim text_items(1 To 5, 1 To 5) As String
Sub Start_multi()

'Items, 5 levels, make room for neighbours (0 and 6)

Dim items(1 To 5, 0 To 6) As Long

Dim i As Long

'Fill out the initial matrix
For i = 1 To 5

   For j = 0 To 6

      items(i, j) = j

   Next j

Next i
'Level 1 - Nationality

text_items(1, 1) = "Brit"

text_items(1, 2) = "Swede"

text_items(1, 3) = "Dane"

text_items(1, 4) = "Norwegian"

text_items(1, 5) = "German"
'Level 2 - Color

text_items(2, 1) = "Red"

text_items(2, 2) = "White"

text_items(2, 3) = "Green"

text_items(2, 4) = "Blue"

text_items(2, 5) = "Yellow"
'Level 3 - Drinks

text_items(3, 1) = "Tea"

text_items(3, 2) = "Coffe"

text_items(3, 3) = "Milk"

text_items(3, 4) = "Beer"

text_items(3, 5) = "Water"
'Level 4 - Cigars

text_items(4, 1) = "Pall Mall"

text_items(4, 2) = "Dunhill"

text_items(4, 3) = "Blends"

text_items(4, 4) = "Blue Master"

text_items(4, 5) = "Prince"
'Level 5 - Pets

text_items(5, 1) = "dogs"

text_items(5, 2) = "birds"

text_items(5, 3) = "cats"

text_items(5, 4) = "horses"

text_items(5, 5) = "fish"
'The idea is to permutate each level.

'Whenever a permutation passes the rules for each level,

'try permutations for the next level

'start the testing , level 1, iteration 1, max=5
Test_multi items(), 1, 1, 5
MsgBox "End of test"

End Sub
Sub Test_multi(items() As Long, level As Long, n As Long, max As Long)
If n = max Then 'reached limit for current level, test for solution

   Test_Solution_Multi items(), level, max

   Exit Sub

End If
'try if current permutation is the solution itsel

Test_multi items(), level, n + 1, max
'swap other items to create permutation for current level

For k = n + 1 To max
  'swap items(level,n) with items(level,k)

  a = items(level, n)

  items(level, n) = items(level, k)

  items(level, k) = a
  'Try it

  Test_multi items(), level, n + 1, max
  'swap back items(level,n) with items(level,k)

  a = items(level, n)

  items(level, n) = items(level, k)

  items(level, k) = a

Next k
End Sub
Sub Test_Solution_Multi(items() As Long, level As Long, max As Long)

Dim i As Long, j As Long

Static count As Long
If level = max Then ' deepest level at test

   If Acording_Rules(items(), level) Then ' if all rules passed then

      'Just print out the solution

      For i = 1 To 5

         For j = 1 To max

             Debug.Print text_items(i, items(i, j)); vbTab;  ' Translate number to readable text

         Next j

         Debug.Print

       Next i
       Debug.Print "»»»»»»»»»»Solution found «««««««««««"
   End If

   Exit Sub

End If
DoEvents
If Acording_Rules(items(), level) Then ' if it passes the rules for this level, try permutations for the next level
   Test_multi items(), level + 1, 1, max

End If

End Sub
Function Acording_Rules(items() As Long, level As Long) As Boolean

  Acording_Rules = False ' assume id doesn't

  Dim i As Long, j As Long

  'Here are the rules
  ' 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 next to, and 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 center 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.
  Select Case level
  Case 1 'Nationality

       'Rule 9

       If items(1, 1)  4 Then Exit Function ' Rule 9
  Case 2 ' Color

       If items(2, 2)  4 Then Exit Function ' Rule 14
       'Rule 1

       For i = 1 To 5

           If items(1, i) = 1 Then

              If items(2, i)  1 Then Exit Function

              Exit For

           End If

       Next i
       'Rule 4

       For i = 1 To 5

           If items(2, i) = 2 Then

              If items(2, i - 1)  3 Then Exit Function

              Exit For

           End If

       Next i

  Case 3 ' Drinks
       'Rule 8

       If items(3, 3)  3 Then Exit Function
       'Rule 3

       For i = 1 To 5

           If items(1, i) = 3 Then

              If items(3, i)  1 Then Exit Function

              Exit For

           End If

       Next i
       'Rule 5

       For i = 1 To 5

           If items(2, i) = 3 Then

              If items(3, i)  2 Then Exit Function

              Exit For

           End If

       Next i
  Case 4 ' Cigars
       'Rule 7
       For i = 1 To 5

           If items(2, i) = 5 Then

              If items(4, i)  2 Then Exit Function

              Exit For

           End If

       Next i
       'Rule 12

       For i = 1 To 5

           If items(3, i) = 4 Then

              If items(4, i)  4 Then Exit Function

              Exit For

           End If

       Next i
       'Rule 13

       For i = 1 To 5

           If items(1, i) = 5 Then

              If items(4, i)  5 Then Exit Function

              Exit For

           End If

       Next i
       'Rule 15

       For i = 1 To 5

           If items(3, i) = 5 Then

              If items(4, i - 1)  3 And items(4, i + 1)  3 Then Exit Function

              Exit For

           End If

       Next i

  Case 5 ' Pet
        'Rule 2

        For i = 1 To 5

           If items(1, i) = 2 Then

              If items(5, i)  1 Then Exit Function

              Exit For

            End If

       Next i
       'Rule 6

       For i = 1 To 5

           If items(4, i) = 1 Then

              If items(5, i)  2 Then Exit Function

              Exit For

           End If

       Next i
      'Rule 11

      For i = 1 To 5

           If items(4, i) = 2 Then

              If items(5, i - 1)  4 And items(5, i + 1)  4 Then Exit Function

              Exit For

           End If

      Next i
      'Rule 10

      For i = 1 To 5

           If items(4, i) = 3 Then

              If items(5, i - 1)  3 And items(5, i + 1)  3 Then Exit Function

              Exit For

         End If

      Next i
  End Select
'If it passes then assume it's ok

Acording_Rules = True

End Function

Comment on Solving Einstein’s Riddle using nondeterministic computing by Alex Miranda

Alex Miranda — Wed, 08 Dec 2010 16:34:11 +0000

What is funny here, though, is that although the final results tables are different, the hints have been laid out in a manner that actually makes the SAME columns, so that still gives ‘The german owns the fishes’.
The second solutions would be, from left to right:
5 – Green – German – Fishes – Coffee – Prince
4 – White – Swede – Dogs – Beer – Bluemaster
3 – Red – Brit – Birds – Milk – Pall Mall
2 – Blue – Dane – Horses – Tea – Blends
1 – Yellow – Norwegian – Cats – Water – Dunhill

Notice the different ordering from the other solution, from left to right:
1 – Yellow – Norwegian – Cats – Water – Dunhill
2 – Blue – Dane – Horses – Tea – Blends
3 – Red – Brit – Birds – Milk – Pall Mall
4 – Green – German – Fishes – Coffee – Prince
5 – White – Swede – Dogs – Beer – Bluemaster

My hats off to Einstein for making the column combinations non-location dependent, although I was really hoping for a different arrangement. =)

Comment on Solving Einstein’s Riddle using nondeterministic computing by Alex Miranda

Alex Miranda — Wed, 08 Dec 2010 16:29:56 +0000

I solved this after I read this post. Again. I had done it years ago. And in doing so now, I found a very interesting thing. Hint 9 and hint 4 turn out to be ambiguous, because Hint 4 gives us a strict placement of two houses (Green is on the left) but Hint 9 leaves open where the first house is: on the extreme right or on the extreme left? This made me try to solve it using the two different interpretations of Hint 9. When placing the Norwegian on the left, that leaves only one place for the Green/White pair, but when the Norwegian is placed on the right, the Green/White pair has two places to go. In fact, though, one of these will be eliminated because it would require the Swede to have dogs AND birds. So we are left with two viable options for the final solution… and they both lead to good solutions (continues…)
W

Comment on Solving Einstein’s Riddle using nondeterministic computing by Ken

Ken — Wed, 08 Dec 2010 08:32:51 +0000

I got to wondering how close to reality my estimate for the 7^40 loop at 1 cycle per loop was. I knew from the beginning that it was much faster than I reasonably could expect. I got curious about how much a loop really would cost. The logic I created had more than just the loop, but not much more. 7^20 is 79,792,266,297,612,001
I set up a loop for 7^20 times. I knew this would take a lot longer than I would be willing to wait so I added logic to cut out of the loop when it has run for 30 seconds. Extrapilating that out, on my 2GH machine, it should complete 7^20 loops in almost 16 years. All you have to do is divide by 2 and multply by 7^20 to get the number of years estimate for 4GH to loop 7^40 times.
Adding commas into the code output I created: Elapsed in Seconds: 30, count: 4,754,390,571
That was close to my loop estimate for a 4GH device in 1 second so this is 15 times slower than I estimated.

1440 is the number of minutes in a day so you should get through 10^13 loops in one day on my machine: 4,754,390,571*2*1440= 13,692,644,844,480

7^20 divided by the loop count for one day divided by the number of days in the year should come up with the number of years to loop 7^20 times.
79,792,266,297,612,001/13,692,644,844,480/365.25=

Here is the 30 second (compressed by removing extra space) script I wrote:

Int64 Loopcnt = 0;
Int64 then = DateTime.Now.Ticks;
Int64 sec = 0;
int delay = 30;
for (byte i1 = 1; i1 < 8 && sec < delay; i1++)
{
sec = (DateTime.Now.Ticks – then) / 10000000;
for (byte i2 = 1; i2 < 8 && sec < delay; i2++)
{ for (byte i3 = 1; i3 < 8; i3++)
{ for (byte i4 = 1; i4 < 8; i4++)
{ for (byte i5 = 1; i5 < 8 && sec < delay; i5++)
{ for (byte i6 = 1; i6 < 8; i6++)
{ for (byte i7 = 1; i7 < 8; i7++)
{ for (byte i8 = 1; i8 < 8 && sec < delay; i8++)
{ for (byte i9 = 1; i9 < 8; i9++)
{ for (byte i10 = 1; i10 < 8; i10++)
{ for (byte i11 = 1; i11 < 8; i11++)
{
sec = (DateTime.Now.Ticks – then) / 10000000;
for (byte i12 = 1; i12 < 8 && sec < delay; i12++)
{ for (byte i13 = 1; i13 < 8; i13++)
{ for (byte i14 = 1; i14 < 8; i14++)
{ for (byte i15 = 1; i15 < 8; i15++)
{ for (byte i16 = 1; i16 < 8; i16++)
{
sec = (DateTime.Now.Ticks – then) / 10000000;
for (byte i17 = 1; i17 < 8 && sec < delay; i17++)
{ for (byte i18 = 1; i18 < 8; i18++)
{ for (byte i19 = 1; i19 < 8; i19++)
{ for (byte i20 = 1; i20 < 8; i20++)
{ Loopcnt++;
} } } } } } } } } } } } } } } } } } } }
sec = (DateTime.Now.Ticks – then) / 10000000;
string txt = "Elapsed in Seconds: " + sec.ToString() + ", count: " + Loopcnt.ToString();
Console.WriteLine(txt);

Comment on Solving Einstein’s Riddle using nondeterministic computing by kaash

kaash — Wed, 08 Dec 2010 06:53:48 +0000

I have solved this using Excel sheet reordered the assumptions in the following way.

1. The Brit lives in a red house.
4. The Green house is next to, and on the left of the White house.
5. The owner of the Green house drinks coffee.
7. The owner of the Yellow house smokes Dunhill.
8. The man living in the center house drinks milk.
9. The Norwegian lives in the first house.
11. The man who keeps horses lives next to the man who smokes Dunhill.
14. The Norwegian lives next to the blue house.
The above could be marked strait.
The order
Norwegian Dane British German Swede is obvious
Now Dane Drinks tea has two places to fit in when you decide for Blues house the rest falls..
3. The Dane drinks tea.
12. The man who smokes Blue Master drinks beer.
13. The German smokes Prince.
2. The Swede keeps dogs as pets.
6. The person who smokes Pall Mall rears birds.
10. The man who smokes Blends lives next to the one who keeps cats.
15. The man who smokes Blends has a neighbor who drinks water.

Comment on Solving Einstein’s Riddle using nondeterministic computing by Ken

Ken — Wed, 08 Dec 2010 04:55:55 +0000

Jordan gave a link to a C# app he wrote to create this. I haven’t written in this language, but I suspect this code is doing something similar to what Jordan did.

Jordan basically created 5^6 (15625) different objects that listed every permutation of all the variables to get every combination. This kind of solution is possible because the number of permutations is so small. I don’t call this non-deterministic, I call it brute force. (This posted solution may not be using brute force.)

Try solving Sudoku using that method and tell me how well that worked out for you… (9^81 permutations.) I once figured out that on a 4GH machine, just looping through 7^40 without doing any validation would take 10^33 years. I wrote somewhat more intellegent code that found 35K solutions on a 2GH machine in 2 minutes. (It still went through millions of iterations of recursive logic.

I’m thinking a real-world solution that short circuits the iterations by using the restraints as soon as possible would work quite well, but if you go through all the possibilities and then check if it is OK, unless the real world problem is easy, you might be in for a world of hurt.

PS Thanks Jordan, I had forgotten about some of the techniques you used. It helps to be reminded of them.

Comment on Solving Einstein’s Riddle using nondeterministic computing by Rubén Barroso

Rubén Barroso — Wed, 08 Dec 2010 00:46:20 +0000

@Scott: Using excel is as good as using backtracking to solve this problem, and more practical/elegant I dare to say. I will look into removing the CAPTCHAs validations. I myself find them a nuisance every now and then. Thanks for the feedback.

@Kerim: I want only to point out that I don’t think that one needs necessarily ‘enough time’ to enjoy the wonderful sensation of thinking, rather, I consider it an ongoing activity you can’t really stop, whether you like it or not. Other thing, do you consider everyone’s own situation determinant in how he ends up using his brain with time? I get upset when I consider the bazillions minds from the so-called 3rd World that are screened off -an lost- just because their lifes don’t let them concentrate on tasks other than the most immediate ones (Ramanujan comes to mind). But otherwise, good points in your reasoning, especially the one related to the intelligent pets -lol. Man, maybe a bit off-topic, but I am just reading Dan Millman’s “The Way of the Peaceful Warrior” and when you said you are “old” (61 old? C’mon, by which standards?), it immediately occurred to me: “This guy speaks like Socrates!”. Only a mere funny thought certainly, the thing is that I’m constantly thinking away and I can’t (want) help it. Thanks very much for sharing your wisdom, Karim.

@Jordan: I am glad that I used the same data abstraction for the houses as other coders. Thanks for linking to your solution!

Comment on Solving Einstein’s Riddle using nondeterministic computing by Jordan

Jordan — Wed, 08 Dec 2010 00:00:03 +0000

If anyone is interested, I posted a solution in C# a few years back:

http://objectmix.com/theory-concepts/11042-whose-fish-oo-solution.html

Jordan

Comment on Solving Einstein’s Riddle using nondeterministic computing by Kerim

Kerim — Tue, 07 Dec 2010 22:58:49 +0000

@Ruben: Your answer is also not bad at all. And if I understood you well, your case meets one of the two conditions, in the least; ‘interest’ that may help you better do your actual work or ‘enough time’ to enjoy the special sensation of thinking In fact, the process of thinking is the only source of real pleasure that I am able to enjoy in my life.
On the other hand, when a man gets older he doesn’t feel the need to test to which level his logic system is capable in solving general problems, instead his interest will be focused in choosing the kind of problems that still need a solution so that when found could be applied into a new product/software for example (by the way, this may your case here).
As you may have already guessed, I am rather an old man (61 years) but when I was 25, I was ready to pay just to hear a new riddle hard to solve.
We may conclude that though all normal people are given somehow the same typical structure for their brain (like having the same model of PC), this doesn’t imply that with time they can use their brain the same way and/or in the same direction. Fortunately it happens this way, otherwise the world (the humankind) couldn’t go on to exist till now. Hard to get? Just imagine all people happen to be like you or I… who will do the other millions jobs… some intelligent pets?
I gave this example because I look to add something. A person with any level of good reasoning will just fill one position among the zillions important ones which wait to be filled. And the irony is that who are in the positions, around the world, from which they can control the masses (including the most intelligent guys) may be too far from our dear 2% above

Comment on Solving Einstein’s Riddle using nondeterministic computing by Camilo

Camilo — Tue, 07 Dec 2010 22:58:29 +0000

@HMav: I solved this one with pen and paper before looking at the solution posted here. The only thing you have to assume is that the german owns the fish, every other bit of information given fills each and every gap.

Comment on Solving Einstein’s Riddle using nondeterministic computing by Scott

Scott — Tue, 07 Dec 2010 20:12:29 +0000

This is not a very difficult problem to solve if one has tools with which to solve it.
I solved this problem using excel.

Web page CAPTCHAs such as the one necessary to submit this comment on the other hand tend to be both difficult and a nuisance to solve.

Take care.

Comment on Solving Einstein’s Riddle using nondeterministic computing by Rubén Barroso

Rubén Barroso — Tue, 07 Dec 2010 18:51:01 +0000

@Alexey: You are right. Sometimes I can’t even keep in my mind one thing, let alone nine But the main point of my program was to apply the stuff explained in Chapter 4 of SICP to an interesting puzzle. Anyway, in my opinion resorting to pencil + paper when trying to solve it is a slightly challenging task. All in all, maybe the actual underlying reason for creating a program to solve it is that I am becoming lazier as I grow older.

@Kerim: I must say what a piece of stupendous philosophical viewpoint. Following that reasoning, it might be that only 2% of the population is born with the brain wiring that is responsible of creating interest for certain types of problems, which would invalidate the statement that “humans are all armed with the same powerful logic system (the typical brain)” and we would be back in square one again. Powerful stuff to think of, thanks!

@enrique: I use Scheme, a dialect of Lisp. I am just doing the exercises of the following book, that uses Scheme to explain programming concepts: http://mitpress.mit.edu/sicp/full-text/book/book.html

@HMav: Well, yeah, but I don’t think we should be that purists in this case. As I explained before, my initial goal was to use the recently acquired knowledge while reading SICP’s Chapter 4.

Comment on Solving Einstein’s Riddle using nondeterministic computing by HMav

HMav — Tue, 07 Dec 2010 17:31:03 +0000

The larger problem with the riddle is that it is never defined if someone owns the fishes at all. The fifth type of pet could be lizards, or martians. The correct answer is that sufficient information is not available to answer the question without making assumptions.

Comment on Solving Einstein’s Riddle using nondeterministic computing by enrique

enrique — Tue, 07 Dec 2010 14:29:15 +0000

Is that LISP?