我试图解决Prolog的一个谜。 谜语是：有两个楼，每一个都有树公寓（每层楼的公寓）的3房，4房之一，5个房间逐一公寓。
达纳，乔尼和诺亚住在建设1.罗恩，大风和阿隆住在2号楼。
乔尼公寓是高于达纳和诺亚。 这意味着，他住在大楼1挪亚和大风三楼住在同一楼层（不同的建筑物）。 罗恩比阿隆一个更大的空间。 罗恩住一个楼以上大风。 在2号楼的最高公寓是5个房间的公寓。
我需要找到了地板每个人都生活。
我写了这个代码：
solve([dana,building1,F1,R1],[noah,building1,F2,R2],[joni,building1,F3,R3],[gale,building2,F4,R4],[ron,building2,F5,R5],[aron,building2,F6,R6]
) :-
L =[[dana,building1,1,3],[dana,building1,1,4],[dana,building1,1,5],[dana,building1,2,3],[dana,building1,2,4],[dana,building1,2,5],[dana,building1,3,3],[dana,building1,3,4],[dana,building1,3,5]
,[noah,building1,1,3],[noah,building1,1,4],[noah,building1,1,5],[noah,building1,2,3],[noah,building1,2,4],[noah,building1,2,5],[noah,building1,3,3],[noah,building1,3,4],[noah,building1,3,5]
,[joni,building1,1,3],[joni,building1,1,4],[joni,building1,1,5],[joni,building1,2,3],[joni,building1,2,4],[joni,building1,2,5],[joni,building1,3,3],[joni,building1,3,4],[joni,building1,3,5]
,[gale,building1,1,3],[gale,building1,1,4],[gale,building1,1,5],[gale,building1,2,3],[gale,building1,2,4],[gale,building1,2,5],[gale,building1,3,3],[gale,building1,3,4],[gale,building1,3,5]
,[ron,building1,1,3],[ron,building1,1,4],[ron,building1,1,5],[ron,building1,2,3],[ron,building1,2,4],[ron,building1,2,5],[ron,building1,3,3],[ron,building1,3,4],[ron,building1,3,5]
,[aron,building1,1,3],[aron,building1,1,4],[aron,building1,1,5],[aron,building1,2,3],[aron,building1,2,4],[aron,building1,2,5],[aron,building1,3,3],[aron,building1,3,4],[aron,building1,3,5]],
F3 > F2,
F3>F1,
F2 == F4,
R5 == R6-1,
F5 == F4+1,
(F4 == 3, R4 == 5;F5 == 3, R5 == 5; F6 == 3, R6 == 5),
del([dana,building1,F1,R1],L,List1),
del([noah,building1,F2,R2],List1,List2),
del([joni,building1,F3,R3],List2,List3),
del([gale,building2,F4,R4],List3,List4),
del([ron,building2,F5,R5],List4,List5),
del([aron,building2,F6,R6],List5,_).
del(X,L,L1) :-
remove(X,L,L1).
但是，当我执行查询：
solve([dana,building1,F1,R1],[noah,building1,F2,R2],[joni,building1,F3,R3],[gale,building2,F4,R4],[ron,building2,F5,R5],[aron,building2,F6,R6]).
我得到：
"Error 22 : Instantiation Error"
任何人？ 我不明白我做错了。
我终于做到了。 这就是答案：
solve([dana,building1,F1,R1],
[noah,building1,F2,R2],
[joni,building1,F3,R3],
[gale,building2,F4,R4],
[ron,building2,F5,R5],
[aron,building2,F6,R6]) :-
assign([1,2,3],[F1,F2,F3]),
assign([1,2,3],[F4,F5,F6]),
assign([3,4,5],[R1,R2,R3]),
assign([3,4,5],[R4,R5,R6]),
F3 > F2,
F3>F1,
F2 =:= F4,
R5 =:= R6-1,
F5 =:= F4+1,
( F4 =:= 3, R4 =:= 5
; F5 =:= 3, R5 =:= 5
; F6 =:= 3, R6 =:= 5
).
assign(_,[]).
assign(Digs,[D|Vars]):-
del(D,Digs,Digs1),
assign(Digs1,Vars).
del(X,L,L1):-
remove(X,L,L1).
% all zebra-like problems solved in CLP or ASP very easy.
% ECLiPSe CLP
:-lib(ic).
ap(Apart1,Rooms1,Apart2,Rooms2) :-
Apart1 = [Dana,Joni,Noah], Rooms1 = [DanaRm,JoniRm,NoahRm],
Apart2 = [Ron,Gale,Aron], Rooms2 = [RonRm,GaleRm,AronRm],
Apart1 :: [1..3], Rooms1 :: [3..5],
Apart2 :: [1..3], Rooms2 :: [3..5],
alldifferent(Apart1), alldifferent(Rooms1),
alldifferent(Apart2), alldifferent(Rooms2),
Joni #= 3, % so Dana Noah = 1..2
Noah #= Gale,
RonRm #= AronRm + 1, % so RonRm = 4..5 and AronRm=3..4
Ron #= Gale + 1, % so Ron = 2..3 and Gale=1..2
% building2 3floor is 5room. Gale cant be 3. so Ron=3 or Aron=3.
% but AronRm cant be 5 so Aron cant be 3. So Ron is 3 and RonRm is 5.
% ...but in search of holy declarativity lets Prolog to figure that :-)
( Ron #= 3, RonRm #= 5
; Gale #= 3, GaleRm #=5
; Aron #= 3, AronRm #=5
),
labeling(Apart1),labeling(Rooms1),
labeling(Apart2),labeling(Rooms2).
solve:-
ap(A1,R1,A2,R2),
write(A1),write(R1),write(A2),write(R2),nl.
run :-
statistics(hr_time, Start),
(\+ (solve, false)),
statistics(hr_time, End), Time is End - Start,
write('All solutions found in '), write(Time), write(' seconds'), nl.
/* hardware: pentium4-1mb-3.0ggz at ddr1-333mhz
software: eclipse-6.2.24 on slackware-14.0
[eclipse 1]: [apart].
apart.pl compiled 4160 bytes in 0.18 seconds
[eclipse 2]: run.
[1, 3, 2][3, 4, 5][3, 2, 1][5, 3, 4]
[1, 3, 2][3, 5, 4][3, 2, 1][5, 3, 4]
[1, 3, 2][4, 3, 5][3, 2, 1][5, 3, 4]
[1, 3, 2][4, 5, 3][3, 2, 1][5, 3, 4]
[1, 3, 2][5, 3, 4][3, 2, 1][5, 3, 4]
[1, 3, 2][5, 4, 3][3, 2, 1][5, 3, 4]
All solutions found in 0.00655293464660645 seconds
more or less, we have only 1 solution. but we not have any info about
size of rooms in first building. and because of that we just get all 6
possibly combinations for it.
*/
