dmcommunity.org challenge Jun 2021 with #Prolog
2021-06-02
My #prolog solution for “Where is gold?” proposed by dmcommunity.org challenge Jun 2021: 0 means empty, 1 means gold
?- solution(Box1,Box2,Box3).
Box1 = Box3, Box3 = 0,
Box2 = 1.
below the code
:-use_module(library(clpfd)).
sentence1( 1,_Box2,_Box3).
not_sentence1(0,_Box2,_Box3).
sentence2( _Box1,0,_Box3).
not_sentence2(_Box1,1,_Box3).
sentence3( 0,_Box2,_Box3).
not_sentence3(1,_Box2,_Box3).
true_only_one_sentence(Box1, Box2, Box3):-
( sentence1(Box1,Box2,Box3), not_sentence2(Box1,Box2,Box3), not_sentence3(Box1,Box2,Box3) ) ;
( not_sentence1(Box1,Box2,Box3), sentence2(Box1,Box2,Box3), not_sentence3(Box1,Box2,Box3) ) ;
( not_sentence1(Box1,Box2,Box3), not_sentence2(Box1,Box2,Box3), sentence3(Box1,Box2,Box3) ).
solution(Box1, Box2, Box3):-
Box1 in 0..1, /* 0 empty, 1 gold */
Box2 in 0..1,
Box3 in 0..1,
Box1 + Box2 + Box3 #= 1, /* only one box contains gold */
true_only_one_sentence(Box1, Box2, Box3).