Rail Cars!

game.erl

-module (game).
-compile([export_all]).

go() ->
	test(lists:seq(250,999)).

test([N|T]) ->
	case match(parse(N), parse(4*N)) of
		true -> io:format("~p~n", [N]);
		false -> no
	end,
	test(T);
test([]) ->
	done.

parse(N) ->
	parse(integer_to_list(N), []).

parse([H|T], Acc) ->
	{Digit, _} = string:to_integer([H]),
	parse(T, [Digit | Acc]);
parse([],Acc) ->
	lists:reverse(Acc).

match([_,A,R],[R,A,_,_]) ->
 	true;
match(_,_) ->
	false.