sashaafm · April 16, 2017 21:27
diff --git a/delete.ex b/delete.ex
 	@doc """
 	Removes a node with 'node_value' from the given 'tree'. Returns :leaf if the
 	node does not exist.
 	"""
 	@spec delete_node(%{}, any) :: %{} | nil

 	def delete_node(tree, node_value) do 
 		if exists?(tree, node_value) do 
 			delete tree, node_value
 		else
 			nil
 		end
 	end

 	defp delete(tree, node_value) do
 		cond do 
 			tree.value == node_value -> del(tree)
 			tree.value <  node_value -> 
 				%{left: tree.left, 
 										value: tree.value, 
 										right: delete(tree.right, node_value)}
 			tree.value > node_value ->
 				%{left: delete(tree.left,node_value),
 										value: tree.value, 
 										right: tree.right}
 		end
 	end

 	defp del(%{left: :leaf,  value: _, right: right}), do: right
 	defp del(%{left: left, value: _, right: :leaf}),   do: left
 	defp del(%{left: left, value: _, right: right}) do 
 		%{left: left, value: min(right), right: delete(right, min(right))}
 	end

 	defp min(%{left: :leaf,  value: val, right: _}), do: val
 	defp min(%{left: left, value: _,   right: _}), do: min left