5 villas Reasoning

5villas.prolog

#!/opt/local/bin/gprolog --consult-file

segment([H1,H2],[H1,H2]):-!.
segment([H1,H2],[H1,H2|_]):-!.
segment([H1,H2],[_,H4|T2]) :- segment([H1,H2],[H4|T2]).
adjacent([H1,H2],L1,L2) :- segment([H1,H2],L1),!;segment([H2,H1],L2),!.


valid_set([],_,_).
valid_set([H|T],Y,AL):- member(H,Y), \+(member(H,AL)), valid_set(T,Y,[H|AL]).
valid_values(L,Y):- valid_set(L,Y,[]).


villas :-

Solution =[
(1,N1,C1,D1,S1,P1),
(2,N2,C2,D2,S2,P2),
(3,N3,C3,D3,S3,P3),
(4,N4,C4,D4,S4,P4),
(5,N5,C5,D5,S5,P5)
],

% 9: Norwegian lives in first villa.
N1=norwegian,

% 8: Man living in the center villa drinks milk.
D3=milk,

valid_values([C1,C2,C3,C4,C5],[green,white,yellow,blue,red]),

% 4: Green villa is left of white villa.
segment([green,white],[C1,C2,C3,C4,C5]),

valid_values([N2,N3,N4,N5],[dane,german,british,swede]),

% 1: British lives in a red villa.
segment([british,red],[N1,C1,N2,C2,N3,C3,N4,C4,N5,C5]),

% 14: Norwegian lives next to blue villa.
segment([norwegian,blue],[N1,C2,N2,C3,N3,C4,N4,C5]),

valid_values([D1,D2,D4,D5],[coffee,beer,water,tea]),

% 5: Green villa owner drinks coffee.
segment([green,coffee],[C1,D1,C2,D2,C3,D3,C4,D4,C5,D5]),

% 3: Dane drinks tea.
segment([dane,tea],[N1,D1,N2,D2,N3,D3,N4,D4,N5,D5]),

valid_values([S1,S2,S3,S4,S5],[pallmall,dunhill,blend,bluemaster,prince]),

% 13: German Smokes Prince.
segment([german,prince],[N1,S1,N2,S2,N3,S3,N4,S4,N5,S5]),

% 12: Owner who smokes Bluemaster drinks beer.
segment([bluemaster,beer],[S1,D1,S2,D2,S3,D3,S4,D4,S5,D5]),

valid_values([P1,P2,P3,P4,P5],[fish,cat,birds,horse,dog]),

% 2: Swede keeps dogs as pets.
segment([swede,dog],[N1,P1,N2,P2,N3,P3,N4,P4,N5,P5]),

% 6: Person who smokes pallmall rears birds.
segment([pallmall,birds],[S1,P1,S2,P2,S3,P3,S4,P4,S5,P5]),

% 7: Owner of yellow vill smokes Dunhill.
segment([yellow,dunhill],[C1,S1,C2,S2,C3,S3,C4,S4,C5,S5]),

% 15: Man who smokes Blend has a neighbor who dinks water.
adjacent([blend,water],[S1,D2,S2,D3,S3,D4,S4,D5],[D1,S2,D2,S3,D3,S4,D4,S5]),

% 10: Man who smokes Blend lives next to the man who keeps cats.
adjacent([blend,cat],[S1,P2,S2,P3,S3,P4,S4,P5],[P1,S2,P2,S3,P3,S4,P4,S5]),

% 11: Man who keeps horses lives next to man who smokes Dunhill.
adjacent([dunhill,horse],[S1,P2,S2,P3,S3,P4,S4,P5],[P1,S2,P2,S3,P3,S4,P4,S5]),

printSol(Solution).


printSol([]).
printSol([H|T]) :- write(H),nl,printSol(T).