CODEWITHSUNDEEP
prologconstraint-programming
Garmagon117
Garmagon117

Reputation: 225

Prolog kenken solver 4 by 4

so i am trying to solve kenken using prolog but i ran into several problems from the start, first of all lets say i run it like kenken([X1,X2,X3,.....X16]). and i want to solve for this x's with rules i defined before. so lets say the first cell has 3 values X1,X2,and X3 and i want to get 2 by using multiplication meaning that X1*X2*X3=2, now how do i set up a rule to see all posible solutions if i had something like that. also how would i tell my x's to only use a range of values 1-4. i tried to do something like 

:- use_module(library(clpr)).
solve([X1,X2,X3]):-
    {X1*X2*X3=2}.

but its gives me a really weird output.

Upvotes: 2

Views: 1065

Answers (2)

mat
mat

Reputation: 40768

Since you reason over integers, not floats, consider using library(clpfd) instead of CLP(R). In SICStus, SWI and YAP, you can constrain a finite domain variable X to the integer range 1-4 with:

X in 1..4

You can use the built-in predicate label/1 to search for concrete solutions. Example with SWI-Prolog:

?- Vars = [A,B,C], A*B*C #= 2, Vars ins 1..4, label(Vars).

yielding:

Vars = [1, 1, 2], A = B, B = 1, C = 2 ;
Vars = [1, 2, 1], A = C, C = 1, B = 2 ;
Vars = [2, 1, 1], A = 2, B = C, C = 1.

Upvotes: 3

Scott Hunter
Scott Hunter

Reputation: 49896

You need the is operator to do arithmetic:

2 is X1*X2*X3

Note that this will not work unless the X's are all bound to numbers.

Upvotes: 0

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