54 lines
1.5 KiB
Perl
54 lines
1.5 KiB
Perl
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||
|
|
% Author: Tom Schrijvers
|
||
|
|
% Email: Tom.Schrijvers@cs.kuleuven.ac.be
|
||
|
|
% Copyright: K.U.Leuven 2004
|
||
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
||
|
|
:- module(a_star,
|
||
|
|
[
|
||
|
|
a_star/4
|
||
|
|
]).
|
||
|
|
|
||
|
|
:- use_module(library(lists)).
|
||
|
|
|
||
|
|
:- use_module(binomialheap).
|
||
|
|
|
||
|
|
:- use_module(find).
|
||
|
|
|
||
|
|
:- use_module(hprolog).
|
||
|
|
|
||
|
|
a_star(DataIn,FinalData,ExpandData,DataOut) :-
|
||
|
|
a_star_node(DataIn,0,InitialNode),
|
||
|
|
empty_q(NewQueue),
|
||
|
|
insert_q(NewQueue,InitialNode,Queue),
|
||
|
|
a_star_aux(Queue,FinalData,ExpandData,EndNode),
|
||
|
|
a_star_node(DataOut,_,EndNode).
|
||
|
|
|
||
|
|
a_star_aux(Queue,FinalData,ExpandData,EndNode) :-
|
||
|
|
delete_min_q(Queue,Queue1,Node),
|
||
|
|
( final_node(FinalData,Node) ->
|
||
|
|
Node = EndNode
|
||
|
|
;
|
||
|
|
expand_node(ExpandData,Node,Nodes),
|
||
|
|
insert_list_q(Nodes,Queue1,NQueue),
|
||
|
|
a_star_aux(NQueue,FinalData,ExpandData,EndNode)
|
||
|
|
).
|
||
|
|
|
||
|
|
final_node(D^Call,Node) :-
|
||
|
|
a_star_node(Data,_,Node),
|
||
|
|
term_variables(Call,Vars),
|
||
|
|
chr_delete(Vars,D,DVars),
|
||
|
|
copy_term(D^Call-DVars,Data^NCall-DVars),
|
||
|
|
call(NCall).
|
||
|
|
|
||
|
|
expand_node(D^Ds^C^Call,Node,Nodes) :-
|
||
|
|
a_star_node(Data,Score,Node),
|
||
|
|
term_variables(Call,Vars),
|
||
|
|
chr_delete(Vars,D,DVars0),
|
||
|
|
chr_delete(DVars0,Ds,DVars1),
|
||
|
|
chr_delete(DVars1,C,DVars),
|
||
|
|
copy_term(D^Ds^C^Call-DVars,Data^EData^Cost^NCall-DVars),
|
||
|
|
term_variables(Node,NVars,DVars),
|
||
|
|
find_with_var_identity(ENode,NVars,(NCall,EScore is Cost + Score,a_star:a_star_node(EData,EScore,ENode)),Nodes).
|
||
|
|
|
||
|
|
a_star_node(Data,Score,Data-Score).
|