Description

Write a Prolog program to search a road route from any city to any other city.
Assumption:
• All the roads bidirectional.
The XLS sheet is converted into csv file using an inbuilt function, then Depth-first search and Best-First Search is applied on the given knowledge base.

Source Code:
:- [library(csv)] .
:- [library(lists)] .
:- dynamic distance/3 .

:- op(1,’xfy’,’csv_’) .

csv(FILE0)
:-
(start) csv_ (FILE0)
.

(start) csv_ (FILE0)
:-
csv:csv_read_file(FILE0,[HEADER|ROWss]) , row__to__list(HEADER,HEADERs) ,
(loop) csv_ (HEADERs,ROWss)
.

(loop) csv_ (_HEADERs,[])
:-
true
.

(loop) csv_ (HEADERs,[ROW|ROWss])
:-
row__to__list(ROW,ROWs) , lists:nth1(1,ROWs,CITY_A) ,
QUERY_A=(lists:nth1(NTH,ROWs,DISTANCE)) , QUERY_B=(NTH > 1) ,
QUERY_C=(lists:nth1(NTH,HEADERs,CITY_B)) ,
QUERY=(QUERY_A,QUERY_B,QUERY_C) ,
ASSERT=assertz(distance(CITY_A,CITY_B,DISTANCE)) , forall(QUERY,ASSERT) , (loop) csv_ (HEADERs,ROWss)
.

row__to__list(ROW,ROWs)
:-
ROW=..[_|ROWs]
.
dfs([[X|Y]|_],X,[X|Y]). dfs([Y|Q],X,FP) :- add(Y,NP), append(NP,Q,NQ),
dfs(NQ,X,FP).

bestfs([[X1|Y1]|_],X1,[X1|Y1]). bestfs([Y1|Q],X1,FP1) :- add(Y1,NP1), append(Q,NP1,Q1), sorting(Q1,NQ1), bestfs(NQ1,X1,FP1). add([N|Y],NP) :- findall([NN,N|Y],
(distance(N,NN,_),
+ member(NN,Y)), NP).

sorting(L,L2) :- swapping(L,L1), !, sorting(L1,L2). sorting(L,L).

swapping([[A1|B1],[A2|B2]|T],[[A2|B2],[A1|B1]|T]) :- hh(A1,W1), hh(A2,W2),
W1>W2.
swapping([X|T],[X|V]) :- swapping(T,V).

hh(State, Value) :- h(State,Value), number(Value), !. hh(State, Value) :- write(‘WrongFunction: ‘), write(h(State, Value)), nl, abort.

h(_,1).

Output: