99 Elm Problems/Problem 69
69.a) Write a function to convert a tree to a string where empty subtrees are represented by a dot. For example, the tree shown in problem P67 is represented as 'abd..e..c.fg...'.
69.b) Construct a tree from a dot notation string.
# # # THIS IS A STUB # # #
Example in Elm:
import Html exposing (text) import List f : Int -> Int -- your implementation goes here main = text (toString (f 0))