Einstein escreveu um enigma. Ele disse que 98% do mundo não conseguiu resolvê-lo.

Eu resolvi esse enigma em cerca de 25 minutos enquanto estava no trem para o trabalho. É basicamente apenas dedução.

O enigma

Existem 5 casas em 5 cores diferentes seguidas.
Em cada casa mora uma pessoa com uma nacionalidade diferente.
Os 5 proprietários bebem um certo tipo de bebida, fumam uma certa marca de charuto e mantêm um certo animal de estimação.
Nenhum proprietário tem o mesmo animal de estimação, fuma a mesma marca de charuto ou bebe a mesma bebida.
Pergunta: Quem é o dono do peixe?

Para resolver esse enigma, Einstein fornece 15 dicas:

1. O britânico vive na casa vermelha.
2. O sueco mantém cães como animais de estimação.
3. O dinamarquês bebe chá.
4. A casa verde fica logo à esquerda da casa branca.
5. O dono da casa verde bebe café.
6. O proprietário que fuma Pall Mall cria pássaros.
7. O dono da casa amarela fuma Dunhill.
8. O proprietário que mora na casa do centro bebe leite.
9. O norueguês vive na primeira casa.
10. O proprietário que fuma Blends mora ao lado de quem mantém gatos.
11. O proprietário que mantém o cavalo mora ao lado de quem fuma Dunhill.
12. O proprietário que fuma Bluemasters bebe cerveja.
13. O alemão fuma Prince.
14. O norueguês vive ao lado da casa azul.
15. O proprietário que fuma Blends mora ao lado de quem bebe água.

Com essas dicas, você pode encontrar uma solução.

Sua tarefa: crie um programa que resolva esse enigma para você. Codificação embutida a solução não é permitida (duh)

É permitido codificar as dicas em qualquer formato.
Exemplo de formato:

//Hints in order
(Nationality:Brit)==(Color:Red)
(Nationality:Swede)==(Pet:Dogs)
(Nationality:Dane)==(Drink: Tea)
(Color:Green)/(Color:White)
(Color:Green)==(Drink:Coffee)
(Smoke:PallMall)==(Pet:Birds)
(Color:Yellow)==(Smoke:Dunhill)
(House:3)==(Drink:Milk)
(Nationality:Norwegian)==(House:1)
(Smoke:Blend)/\(Pet:Cats)

== significa igual a
/ significa no lado esquerdo de
\ significa no lado direito de
/ \ significa esquerdo ou direito de

Como eu disse, é permitido codificar dicas ou tê-las como entrada.

Saída: A saída deve estar no seguinte formato (com os valores corretos, apenas dizendo para os trolls;))

 _____________    _____________    _____________    _____________    _____________
|   Number    |  |   Number    |  |   Number    |  |   Number    |  |   Number    |
| Nationality |  | Nationality |  | Nationality |  | Nationality |  | Nationality |
|    Color    |  |    Color    |  |    Color    |  |    Color    |  |    Color    |
|    Drink    |  |    Drink    |  |    Drink    |  |    Drink    |  |    Drink    |
|    Smoke    |  |    Smoke    |  |    Smoke    |  |    Smoke    |  |    Smoke    |
|     Pet     |  |     Pet     |  |     Pet     |  |     Pet     |  |     Pet     |
---------------  ---------------  ---------------  ---------------  ---------------

The <Nationality> in the <Color> house owns the fish!

As caixas de arte ASCII podem ser alteradas por você, desde que sejam caixas, não importando quais símbolos você usar.

Qualquer conhecimento sobre esse enigma e solução não pode ser usado no programa. Deve usar lógica pura e dedução para resolver o enigma.

Marcado como codegolf, mas pode ser um desafio para o código, não tenho certeza. Quaisquer pensamentos sobre os critérios de vencimento para um desafio de código, fique à vontade para compartilhar :)

Por enquanto, isso é código-golfe, e o programa com o menor número de bytes vence.

Boa sorte e codificação feliz :)

Prolog - 954 caracteres

m(A,Z):-member(A,Z).
e:-e(Z),w(Z).
e(Z):-Z=[[1,A,F,K,P,U],[2,B,G,L,Q,V],[3,C,H,M,R,W],[4,D,I,N,S,X],[5,E,J,O,T,Y]],m([_,b,r,_,_,_],Z),m([_,s,_,d,_,_],Z),m([_,d,_,_,t,_],Z),m([WH,_,w,_,_,_],Z),m([GH,_,g,_,_,_],Z),GH=:=WH-1,m([_,_,g,_,c,_],Z),m([_,_,_,b,_,p],Z),m([_,_,y,_,_,d],Z),m([3,_,_,_,m,_],Z),m([1,n,_,_,_,_],Z),m([BH,_,_,_,_,b],Z),m([CH,_,_,c,_,_],Z),(BH=:=CH+1;BH=:=CH-1),m([DH,_,_,_,_,d],Z),m([HH,_,_,h,_,_],Z),(HH=:=DH+1;HH=:=DH-1),m([_,_,_,_,b,l],Z),m([_,g,_,_,_,r],Z),m([NH,n,_,_,_,_],Z),m([YH,_,b,_,_,_],Z),(NH=:=YH+1;NH=:=YH-1),m([SH,_,_,_,_,b],Z),m([XH,_,_,_,w,_],Z),(SH=:=XH+1;SH=:=XH-1),p([n,d,b,g,s],[A,B,C,D,E]),p([y,b,r,g,w],[F,G,H,I,J]),p([c,h,b,f,d],[K,L,M,N,O]),p([w,t,m,c,b],[P,Q,R,S,T]),p([d,b,p,r,l],[U,V,W,X,Y]).
t(X,[X|R],R).
t(X,[F|R],[F|S]):-t(X,R,S).
p([W|X],Y):-p(X,V),t(W,Y,V).
p([],[]).
b:-write('+--+--+--+--+--+--+'),nl.
z(A):-writef('|%2L|%2L|%2L|%2L|%2L|%2L|',A),nl.
w([A,B,C,D,E]):-b,z(A),z(B),z(C),z(D),z(E),b.

Resultado

+--+--+--+--+--+--+
|1 |n |y |c |w |d |
|2 |d |b |h |t |b |
|3 |b |r |b |m |p |
|4 |g |g |f |c |r |
|5 |s |w |d |b |l |
+--+--+--+--+--+--+

Chave:

• Primeira coluna é o número da casa;
• Segunda coluna é nacionalidade;
• Terceira coluna é a cor favorita;
• Quarta coluna é animal de estimação;
• Quinta coluna é bebida; e
• A sexta coluna é o cigarro (r = príncipe, l = bluemaster).

Ruby 322 + entrada 442

Pesquisa por força bruta de quase 25 bilhões de respostas possíveis.
Meu computador levaria cerca de 75 dias para executar este programa.
Eu nunca verifiquei se este programa imprime uma resposta correta!

Correr como ruby riddle.rb < riddle.in

riddle.rb (332 bytes)

g=readlines
v=g.shift(5).map &:split
c,*d=v.map{|a|[*a.permutation]}
c.product(*d){|a|(f=eval a.map{|b|b.each_with_index.map{|s,i|"#{s}=#{i}\n"}.join}.join+'g.map{|h|eval h}.all?&&fish')&&(r=['-----------']*5
puts [r,[*0..4],*a,r].map{|s|s.map{|t|'|%11s|'%t}.join},"The #{a[0][f]} in the #{a[1][f]} house owns the fish!")}

riddle.in (442 bytes)

brit dane german norwegian swede
blue green red white yellow
beer coffee milk tea water
blends bluemasters dunhill pall_mall prince
birds cats dogs fish horse
brit==red
swede==dogs
dane==tea
green==white-1
green==coffee
pall_mall==birds
yellow==dunhill
2==milk
norwegian==0
blends==cats-1||blends==cats+1
horse==dunhill-1||horse==dunhill+1
bluemasters==beer
german==prince
norwegian==blue-1||norwegian==blue+1
blends==water-1||blends==water+1

O arquivo de entrada deve conter 5 linhas de nomes, seguidas por linhas de expressões lógicas. Os números das casas são de 0 a 4. Deve haver a fish.

O programa liga Array#permutationcinco vezes para encontrar todas as maneiras de ordenar as matrizes de nacionalidades, cores, bebidas, cigarros e animais de estimação. O longo ciclo é c.product(*d){|a|...}, chamando Array#productpara iterar quase 25 bilhões de respostas possíveis. O corpo do loop tem a forma (f=eval ...)&&(...). A eval ...parte avalia as expressões lógicas. Se tudo é verdade, então fé o número da casa do peixe e a &&(...)parte imprime a resposta. O número da casa 0 é verdadeiro no Ruby.

Código golf significa não adicionar código para velocidade! Mas faltam 75 dias para executar o programa!

Prolog, 653 caracteres

a([],L,L).
a([H|T],L2,[H|L3]):-a(T,L2,L3).
m(X,L):-a(_,[X|_],L).
r(X,Y,L):-a(_,[X,Y|_],L).
n(X,Y,L):-r(X,Y,L);r(Y,X,L).
s:-s(S),w(S).
s(S):-length(S,5),m([b,r,_,_,_],S),m([s,_,_,_,d],S),m([d,_,t,_,_],S),r([_,g,_,_,_],[_,w,_,_,_],S),m([_,g,c,_,_],S),m([_,_,_,p,b],S),m([_,y,_,d,_],S),S=[_,_,[_,_,m,_,_],_,_],S=[[n,_,_,_,_],_,_,_,_],n([_,_,_,b,_],[_,_,_,_,c],S),n([_,_,_,d,_],[_,_,_,_,h],S),m([_,_,b,l,_],S),m([g,_,_,r,_],S),n([n,_,_,_,_],[_,b,_,_,_],S),n([_,_,_,b,_],[_,_,w,_,_],S),m([_,_,_,_,f],S).
b:-write('----------------+'),nl.
z(Y,A):-write(Y),writef('|%2L|%2L|%2L|%2L|%2L|',A),nl.
w([S1,S2,S3,S4,S5]):-b,z(1,S1),z(2,S2),z(3,S3),z(4,S4),z(5,S5),b.

Smalltalk 1332 caracteres

Usando Smalltalk simples:

|n c v g p t r|n:=#(Brit Swede Dane Norwegian German
Red Green White Yellow Blue
Tea Coffee Milk Beer Water
PallMall Dunhill Blends Bluemasters Prince
Dogs Birds Cats Horses Fish).
v:=Dictionary new.n do:[:n|v at:n put:nil].g:=n splitForSize:5.
c:={{[:b :r|b==r].#Brit.#Red}.{[:s :d|s==d].#Swede.#Dogs}.{[:d :t|d==t].#Dane.#Tea}.
{[:g :w|g==(w-1)].#Green.#White}.{[:g :c|g==c].#Green.#Coffee}.
{[:p :b|p==b].#PallMall.#Birds}.{[:y :d|y==d].#Yellow.#Dunhill}.
{[:m|m==3].#Milk}.{[:n|n==1].#Norwegian}.{[:b :c|(b-c)abs==1].#Blends.#Cats}.
{[:h :d|(h-d)abs==1].#Horses.#Dunhill}.{[:m :b|m==b].#Bluemasters.#Beer}.
{[:g :p|g==p].#German.#Prince}.{[:n :b|(n-b)abs==1].#Norwegian.#Blue}.
{[:b :w|(b-w)abs==1].#Blends.#Water}}.
t:=[:c|x:=(c from:2collect:[:n|v at:n]).(x includes:nil)or:[c first valueWithArguments:x]].
p:=[|f|(((''-'',* 16),'' ''),*5)printCR.g do:[:n||w|w:=n collect:[:n|v at:n].w sortWith:n.
n do:[:n|''|''print.(n centerPaddedTo:14)print.''| ''print].''''printCR.].(((''-'',* 16),'' ''),*5)printCR.
f:=v at:#Fish.(''The %1 in the %2 house owns the fish''bindWith:(g first detect:[:n|(v at:n)==f])with:((g at:2) detect:[:n|(v at:n)==f]))printCR].
r:=[:gi|gi==0ifTrue:p ifFalse:[#(1 2 3 4 5)permutationsDo:[:perm|v declareAll:(g at:gi)from:perm.
(c conform:t)ifTrue:[r value:gi-1]].v declareAll:(g at:gi)from:#(nil),*5]].
r value:g size.

Resultado:

---------------- ---------------- ---------------- ---------------- ---------------- 
|  Norwegian   | |     Dane     | |     Brit     | |    German    | |    Swede     | 
|    Yellow    | |     Blue     | |     Red      | |    Green     | |    White     | 
|    Water     | |     Tea      | |     Milk     | |    Coffee    | |     Beer     | 
|   Dunhill    | |    Blends    | |   PallMall   | |    Prince    | | Bluemasters  | 
|     Cats     | |    Horses    | |    Birds     | |     Fish     | |     Dogs     | 
---------------- ---------------- ---------------- ---------------- ----------------
The German in the Green house owns the fish

Como a versão golfada é quase ilegível, eis o código do desenvolvedor com nomes próprios, indentação e espaços para facilitar a leitura:

|names constraints foundSolution v groups printSolution testC test try|

names := #(Brit Swede Dane Norwegian German
 Red Green White Yellow Blue
 Tea Coffee Milk Beer Water
 PallMall Dunhill Blends Bluemasters Prince
 Dogs Birds Cats Horses Fish).

v := Dictionary new.
names do:[:n | v at:n put:nil].
groups := names splitForSize:5.

constraints := {
        {[:b :r | b==r] . #Brit . #Red   }.          "/ The Brit lives in the red house.
        {[:s :d | s==d] . #Swede . #Dogs }.          "/ The Swede keeps dogs as pets.
        {[:d :t | d==t] . #Dane . #Tea   }.          "/ The Dane drinks tea.
        {[:g :w | g==(w-1)] . #Green . #White }.     "/ The green house is on the immediate left of the white house.
        {[:g :c | g==c] . #Green . #Coffee}.         "/ The green house's owner drinks coffee.
        {[:p :b | p==b] . #PallMall . #Birds}.       "/ The owner who smokes Pall Mall rears birds.
        {[:y :d | y==d] . #Yellow . #Dunhill}.       "/ The owner of the yellow house smokes Dunhill.
        {[:m | m==3] . #Milk}.                       "/ The owner living in the center house drinks milk.
        {[:n | n==1] . #Norwegian }.                 "/ The Norwegian lives in the first house.
        {[:b :c | (b-c)abs==1] . #Blends . #Cats}.   "/ The owner who smokes Blends lives next to the one who keeps cats.
        {[:h :d | (h-d)abs==1] . #Horses . #Dunhill}."/ The owner who keeps the horse lives next to the one who smokes Dunhill.
        {[:m :b | m==b] . #Bluemasters . #Beer}.     "/ The owner who smokes Bluemasters drinks beer.
        {[:g :p | g==p] . #German . #Prince}.        "/ The German smokes Prince.
        {[:n :b | (n-b)abs==1] . #Norwegian . #Blue}."/ The Norwegian lives next to the blue house.
        {[:b :w | (b-w)abs==1] . #Blends . #Water}.  "/ The owner who smokes Blends lives next to the one who drinks water.
}.
testC := [:c | vi:=((c from:2) collect:[:n|v at:n]). (vi includes:nil) or:[c first valueWithArguments:vi]].
test := [constraints conform:testC].

printSolution :=
 [  |f|
    ((('-',* 16),' '),*5) printCR.
    groups do:[:names|
         |values|
         values := names collect:[:nm|v at:nm].
         values sortWith:names.
         names do:[:n| '|'print. (n centerPaddedTo:14)print.'| ' print].
         '' printCR.
    ].
    ((('-',* 16),' '),*5) printCR.
    f := v at:#Fish.
    ('The %1 in the %2 house owns the fish'
        bindWith:((groups at:1) detect:[:n|(v at:n)==f])
        with:((groups at:2) detect:[:n|(v at:n)==f]))printCR
 ].


try := [:gi |
    gi == 0 
     ifTrue: printSolution
     ifFalse:[
        (1 to:5) asArray permutationsDo:[:perm |
            v declareAll:(groups at:gi) from:perm.
            test value ifTrue:[
                try value:(gi-1).
            ].
        ].
        v declareAll:(groups at:gi) from:#(nil nil nil nil nil).
    ].
].
try value:groups size.

Usando uma biblioteca do solucionador de restrições:

Usando uma biblioteca de resolução de restrições, que é muito semelhante à descrita no manual OZ / Mozart. Como eu espero que você se queixe de que isso não é válido para o concurso ;-), ele é adicionado apenas para sua diversão e inspiração (procure um pacote de contraint no seu idioma), sem golf e sem contar caracteres.

|solution|

solution := Solver
    anySolutionFor:[
        |Brit Swede Dane Norwegian German
         Red Green White Yellow Blue
         PallMall Dunhill Prince Blends Bluemasters
         Tea Coffee Water Beer Milk
         Dogs Birds Cats Horses Fish|

        Brit        := (1 %% 5) name:#Brit.
        Swede       := (1 %% 5) name:#Swede.
        Dane        := (1 %% 5) name:#Dane.
        Norwegian   := (1 %% 5) name:#Norwegian.
        German      := (1 %% 5) name:#German.

        Red     := (1 %% 5) name:#Red.
        Green   := (1 %% 5) name:#Green.
        White   := (1 %% 5) name:#White.
        Yellow  := (1 %% 5) name:#Yellow.
        Blue    := (1 %% 5) name:#Blue.

        PallMall     := (1 %% 5) name:#PallMall.
        Dunhill      := (1 %% 5) name:#Dunhill.
        Prince       := (1 %% 5) name:#Prince.
        Blends       := (1 %% 5) name:#Blends.
        Bluemasters  := (1 %% 5) name:#Bluemasters.

        Tea    := (1 %% 5) name:#Tea.
        Coffee := (1 %% 5) name:#Coffee.
        Milk   := (1 %% 5) name:#Milk.
        Water  := (1 %% 5) name:#Water.
        Beer   := (1 %% 5) name:#Beer.

        Dogs         := (1 %% 5) name:#Dogs.
        Birds        := (1 %% 5) name:#Birds.
        Cats         := (1 %% 5) name:#Cats.
        Horses       := (1 %% 5) name:#Horses.
        Fish         := (1 %% 5) name:#Fish.

        Solver allDistinct:{ Brit . Swede . Dane . Norwegian . German. }.
        Solver allDistinct:{ Red. Green. White. Yellow. Blue. }.
        Solver allDistinct:{ PallMall. Dunhill. Prince. Blends. Bluemasters. }.
        Solver allDistinct:{ Tea. Coffee. Milk. Water. Beer }.
        Solver allDistinct:{ Dogs. Birds. Cats. Horses. Fish. }.

        Brit       =: Red.           "/ The Brit lives in the red house.
        Swede      =: Dogs.          "/ The Swede keeps dogs as pets.
        Dane       =: Tea.           "/ The Dane drinks tea.
        Green =: (White - 1).        "/ The green house is on the immediate left of the white house.
        Green =: Coffee.             "/ The green house's owner drinks coffee.
        PallMall   =: Birds.         "/ The owner who smokes Pall Mall rears birds.
        Yellow =: Dunhill.           "/ The owner of the yellow house smokes Dunhill.
        Milk =: 3.                   "/ The owner living in the center house drinks milk.
        Norwegian =: 1.              "/ The Norwegian lives in the first house.
        (Blends - Cats) abs =: 1.    "/ The owner who smokes Blends lives next to the one who keeps cats.
        (Horses - Dunhill) abs =: 1. "/ The owner who keeps the horse lives next to the one who smokes Dunhill.
        Bluemasters =: Beer.         "/ The owner who smokes Bluemasters drinks beer.
        German =: Prince.            "/ The German smokes Prince.
        (Norwegian - Blue) abs =: 1. "/ The Norwegian lives next to the blue house.
        (Blends - Water) abs =: 1.   "/ The owner who smokes Blends lives next to the one who drinks water.
    ].

solution printCR.

Observe o operador "=:", que significa "unificar com". O solucionador usa um algoritmo de retorno no conjunto de restrições definidas no bloco do problema. O código restante imprime a solução em caixas:

    |pLine pSorted f |

    pLine := [ 
        (1 to:5) do:[:i | ('-' ,* 15) print] separatedBy:[' ' print].
        '' printCR.
    ].
    pSorted := [:keys |
        |items t|

        items := keys collect:[:k| solution at:k].
        t := keys copy. items values sortWith:t. 
        pLine value:(t collect:[:x | '| ',(x centerPaddedTo:11),' |']).
    ].

    pLine value.
    pSorted value:#( Brit Swede Dane Norwegian German ).
    pSorted value:#( Red Green White Yellow Blue ).
    pSorted value:#( Tea Coffee Milk Water Beer ).
    pSorted value:#( PallMall Dunhill Prince Blends Bluemasters ).
    pSorted value:#( Dogs Birds Cats Horses Fish ).
    pLine value.

    f := solution at:'Fish'.
    ('The %1 in the %2 house owns the fish!'
        bindWith:(#( Brit Swede Dane Norwegian German ) detect:[:n| (solution at:n) == f])
        with:(#( Red Green White Yellow Blue ) detect:[:n| (solution at:n) == f])
            ) printCR.

Resultado:

Solution(Brit->3 Swede->5 Dane->2 Norwegian->1 German->4 Red->3 Green->4
 White->5 Yellow->1 Blue->2 PallMall->3 Dunhill->1 Prince->4 Blends->2
 Bluemasters->5 Tea->2 Coffee->4 Milk->3 Water->1 Beer->5 Dogs->5 Birds->3
 Cats->1 Horses->2 Fish->4)
--------------- --------------- --------------- --------------- ---------------
|  Norwegian  | |    Dane     | |    Brit     | |   German    | |    Swede    |
|   Yellow    | |    Blue     | |     Red     | |    Green    | |    White    |
|    Water    | |     Tea     | |    Milk     | |   Coffee    | |    Beer     |
|   Dunhill   | |   Blends    | |  PallMall   | |   Prince    | | Bluemasters |
|    Cats     | |   Horses    | |    Birds    | |    Fish     | |    Dogs     |
--------------- --------------- --------------- --------------- ---------------
The German in the Green house owns the fish!

Edit: oops - esqueci de imprimir a linha "quem é o dono do peixe" na versão simples.

Ruby 1166 caracteres

Editar: atualizado para o formato de saída correto

É executado consistentemente em menos de 0,2 segundos em um MBP i5.

Fonte: Visualizar no Github

Uma linha:

def q(a);a.permutation;end;def z(a,b,c,d);l(a,b,c,d)||l(c,d,a,b);end;def l(a,b,c,d);(0..4).any?{|i|a[i]==b&&c[i+1]==d};end;def i(a,b,c,d);(0..4).any?{|i|a[i]==b&&c[i]==d};end;def t(i);['White','Yellow','Blue','Red','Green','German','Swede','Brit','Norwegian','Dane','Birds','Cats','Horses','Fish','Dogs','Beer','Water','Tea','Milk','Coffee','Blends','PallMall','Prince','Bluemasters','Dunhill'][i];end;def y(s);l=13-s.length;'|'+' '*(l/2.0).floor+s+' '*(l/2.0).ceil+'|';end;def d(s);b=[' '+(0..4).map{'_'*13}.join(' '*4)];u='  ';b<<[1,2,3,4,5].map{|i|y(i.to_s)}.join(u);s.each{|i|b<<i.map{|j|y(t(j))}.join(u)};b<<(0..4).map{'-'*15}.join(u);b<<'';z=s[4].index(13);b<<"The #{t s[0][z]} in the #{t s[1][z]} house owns the fish!";b.join "\n";end;q([0,1,2,3,4]).each{|c|l(c,4,c,0)||next;q([5,6,7,8,9]).each{|n|i(n,7,c,3)||next;n[0]==8||next;z(n,8,c,2)||next;q([10,11,12,13,14]).each{|a|i(n,6,a,14)||next;q([15,16,17,18,19]).each{|d|d[2]==18||next;i(c,4,d,19)||next;i(n,9,d,17)||next;q([20,21,22,23,24]).each{|s|z(a,12,s,24)||next;i(s,21,a,10)||next;z(s,20,d,16)||next;z(s,20,a,11)||next;i(n,5,s,22)||next;i(c,1,s,24)||next;i(s,23,d,15)||next;puts d([n,c,d,s,a]);exit}}}}}

Acolchoado com novas linhas para caber na página:

def q(a);a.permutation;end;def z(a,b,c,d);l(a,b,c,d)||l(c,d,a,b);end
def l(a,b,c,d);(0..4).any?{|i|a[i]==b&&c[i+1]==d};end;def i(a,b,c,d);
(0..4).any?{|i|a[i]==b&&c[i]==d};end;def t(i);['White','Yellow','Blue',
'Red','Green','German','Swede','Brit','Norwegian','Dane','Birds',
'Cats','Horses','Fish','Dogs','Beer','Water','Tea','Milk','Coffee',
'Blends','PallMall','Prince','Bluemasters','Dunhill'][i];end;def y(s);
l=13-s.length;'|'+' '*(l/2.0).floor+s+' '*(l/2.0).ceil+'|';end;
def d(s);b=[' '+(0..4).map{'_'*13}.join(' '*4)];u='  ';
b<<[1,2,3,4,5].map{|i|y(i.to_s)}.join(u);s.each{|i|b<<i.map{|j|
y(t(j))}.join(u)};b<<(0..4).map{'-'*15}.join(u);b<<'';
z=s[4].index(13);
b<<"The #{t s[0][z]} in the #{t s[1][z]} house owns the fish!";
b.join "\n";end;q([0,1,2,3,4]).each{|c|l(c,4,c,0)||next;
q([5,6,7,8,9]).each{|n|i(n,7,c,3)||next;n[0]==8||next;z(n,8,c,2)||next;
q([10,11,12,13,14]).each{|a|i(n,6,a,14)||next;
q([15,16,17,18,19]).each{|d|d[2]==18||next;i(c,4,d,19)||next;
i(n,9,d,17)||next;q([20,21,22,23,24]).each{|s|z(a,12,s,24)||next;
i(s,21,a,10)||next;z(s,20,d,16)||next;z(s,20,a,11)||next;i(n,5,s,22)||next;
i(c,1,s,24)||next;i(s,23,d,15)||next;puts d([n,c,d,s,a]);exit}}}}}

Saídas:

 _____________    _____________    _____________    _____________    _____________
|      1      |  |      2      |  |      3      |  |      4      |  |      5      |
|  Norwegian  |  |    Dane     |  |    Brit     |  |   German    |  |    Swede    |
|   Yellow    |  |    Blue     |  |     Red     |  |    Green    |  |    White    |
|    Water    |  |     Tea     |  |    Milk     |  |   Coffee    |  |    Beer     |
|   Dunhill   |  |   Blends    |  |  PallMall   |  |   Prince    |  | Bluemasters |
|    Cats     |  |   Horses    |  |    Birds    |  |    Fish     |  |    Dogs     |
---------------  ---------------  ---------------  ---------------  ---------------

The German in the Green house owns the fish!

Código Ungolfed

@colors        = [:white, :yellow, :blue, :red, :green].shuffle.permutation
@cigars        = [:blends, :pall_mall, :prince, :bluemasters, :dunhill].shuffle.permutation
@nationalities = [:german, :swedish, :british, :norwegian, :danish,].shuffle.permutation
@drinks        = [:beer, :water, :tea, :milk, :coffee].shuffle.permutation
@pets          = [:birds, :cats, :horses, :fish, :dogs].shuffle.permutation

def next_to?(set_a, val_a, set_b, val_b)
  left_of?(set_a, val_a, set_b, val_b) ||
  left_of?(set_b, val_b, set_a, val_a)
end

def left_of?(set_a, val_a, set_b, val_b)
  (0..4).any? do |i|
    set_a[i]   == val_a &&
    set_b[i+1] == val_b
  end
end

def implies?(set_a, val_a, set_b, val_b)
  (0..4).any? do |i|
    set_a[i] == val_a &&
    set_b[i] == val_b
  end
end

def solve
  i = 0
  @colors.each do |colors|
    i += 1
    next unless left_of?(colors, :green, colors, :white)
    @nationalities.each do |nationalities|
      i += 1
      next unless implies?(nationalities, :british, colors, :red)
      next unless nationalities[0] == :norwegian
      next unless next_to?(nationalities, :norwegian, colors, :blue)
      @pets.each do |pets|
        i += 1
        next unless implies?(nationalities, :swedish, pets, :dogs) 
        @drinks.each do |drinks|
          i += 1
          next unless drinks[2] == :milk
          next unless implies?(colors, :green, drinks, :coffee)
          next unless implies?(nationalities, :danish, drinks, :tea)
          @cigars.each do |cigars|
            i += 1
            next unless next_to?(pets, :horses, cigars, :dunhill)
            next unless implies?(cigars, :pall_mall, pets, :birds)
            next unless next_to?(cigars, :blends, drinks, :water)
            next unless next_to?(cigars, :blends, pets, :cats)
            next unless implies?(nationalities , :german, cigars, :prince)
            next unless implies?(colors, :yellow, cigars, :dunhill)
            next unless implies?(cigars, :bluemasters,  drinks, :beer)
            return [colors, nationalities, pets, drinks, cigars], i
          end
        end
      end
    end
  end
end

class Symbol
  def humanize
    result = self.to_s
    result.gsub!('_', ' ')
    result.split(' ').collect{|part| part.capitalize }.join(' ')
  end
end

solution, attempts = solve

puts "\nSolved in #{attempts} attempts.\n\n"

for i in (0..4)
  number, color, nationality, cigar, drink, pet = i+1, solution[0][i], solution[1][i].humanize, solution[4][i].humanize, solution[3][i], solution[2][i]
  puts "House #{number} is #{color}. The owner is #{nationality}, smokes #{cigar}, drinks #{drink}, and keeps #{pet}."
end

puts "\n"

Saídas:

Solved in 37663 attempts.

House 1 is yellow. The owner is Norwegian, smokes Dunhill, drinks water, and keeps cats.
House 2 is blue. The owner is Danish, smokes Blends, drinks tea, and keeps horses.
House 3 is red. The owner is British, smokes Pall Mall, drinks milk, and keeps birds.
House 4 is green. The owner is German, smokes Prince, drinks coffee, and keeps fish.
House 5 is white. The owner is Swedish, smokes Bluemasters, drinks beer, and keeps dogs.

O uso shufflena configuração inicial garante caminhos de solução exclusivos sempre. Você pode ver isso pelo número de tentativas alteradas entre as execuções. Isso atenua a necessidade de alimentar a entrada separadamente, embora a alteração do código para isso seja trivial.