Please Help me with this Problem

[xonTAB]

I was working on the following problem:

The Cartesian Product of two sets is the set containing all the tuples produced from one element of one set and second element from the other set. Consider the sets A = {a, b, c} and B = {1, 2, 3}
The cartesian product of A and B = A ? B
= { (a,1), (a,2), (a,3), (b,1), (b,2), (b,3), (c,1), (c,2), (c,3) }


Write a Prolog program in which it is possible to issue goals to display all the tuples produced from the Cartesian Product of any two sets, including the empty set.
e.g. cartesian_product ([a,b,c],[1,2,3]) would display:
a 1 a 2 a 3
b 1 b 2 b 3
c 1 c 2 c 3

How can you do it using Prolog?

Shaun Tabone

http://xontab.tk

 

[madarb]

cartesian_product([H|T],B):- cartesian_product_1(H,B),cartesian_product(T,B).


cartesian_product_1(H,[H1,T1]):- put(H),write( {*spaces*} ),
put(H1),cartesian_product_1(H,T1).


its just a thought.i dont know whether it works, i didnt run it.if i had this problem this is what id think first.

if it happens that you dont understand,

cartesian_product takes each member of the first list and sends it to cartesian_product_1 along with the second list.then cartesian_product_1 puts on the screen every pair the members of the second list produce with the member of the first list passed from cartesian_product.

hope you get what i mean.

if it doesnt work think on it on your own but i guess it could be whole wrong.

 

[xonTAB]

Thanks Very Much. I tried to run your code but did not work. I tried to modify it a bit and it finally it worked.

cartesian_product([H|T],B):- cartesian_product_1(H,B),
nl,cartesian_product(T,B).
cartesian_product_1(H,[]).
cartesian_product_1(H,[H1|T1]):- write(H),
write(H1),write(' '),cartesian_product_1(H,T1).

Thanks a lot for your help.

 

[madarb]

happy to help man
sorry for the mistakes as i said before its just what crossed my mind.