Search Algorithms

[Kelly]

Hello all,

I have some search algorithms implemented in a program, which I can not modify. I also have a labyrinth represented in the picture:

I can implement the labyrinth in any way I want. But I'm not getting the correct result with my implementation. My question is: how can I represent the labyrinth in a way that produces the correct result?

I appreciate any help.

Here follows the code:

start(r1:_).

goal(_:r8).

action(go(P,Q),P,Q,D) :- link(P,Q,D).

link(r1,r2,1).

link(r1,r3,1).

link(r1,r4,1).

link(r1,r5,1).

link(r2,r6,1).

link(r2,r7,1).

link(r3,r6,1).

link(r3,r7,1).

link(r4,r7,1).

link(r4,r8,1).

link(r6,r9,1).

h(_,0).

%------------------------------

%I Can`t modify code from here

%------------------------------

search(T) :-

   start(E),

   search(T,[_:_:0:E:[]],[],P:G),

   type(T,N),

   format('~nTipo.: ~w',[N]),

   format('~nPlano: ~w',[P]),

   format('~nCusto: ~w~n~n',[G]).

search(_,[_:_:G:E:C|_],_,P:G) :-

   goal(E), !,

   reverse(C,P).

search(T,[_:_:G:E:C|F],V,P) :-

   suc(T,G:E:C,V,S),

   insert(T,S,F,NF),

   union([E],V,NV),

   search(T,NF,NV,P).

suc(T,G1:E:C,V,R) :-

   findall(F:H:G:S:[A|C],

  (action(A,E,S,G),

   not(member(S,V)),

   h(S,H), G is G1+G2,

   (T=4 -> F is G

   ;T=5 -> F is H

   ;T=6 -> F is G+H

   ;       F is 0)),R).

insert(1,S,F,NF) :- append(S,F,R),

                    length(R,L), shuffle(L,R,NF), !.

insert(2,S,F,NF) :- append(F,S,NF), !.

insert(3,S,F,NF) :- append(S,F,NF), !.

insert(_,S,F,NF) :- append(S,F,R), sort(R,NF), !.

shuffle(0,F,F) :- !.

shuffle(L,F,[X|NF]) :-

   N is random(L),

   nth0(N,F,X), delete(F,X,R),

   M is L-1,

   shuffle(M,R,NF), !.

type(1,aleatória).

type(2,breadth_first_search).

type(3,depth_first_search).

type(4,menor_custo).

type(5,melhor_estimativa).

type(6,a_search).