class Tree
  attr_accessor :value, :left, :right
  def initialize(value, left=nil, right=nil)
    @value = value
    @left = left
    @right = right
  end

  def each_node(&block)
    block.call(@value)
    @left.each_node(&block) if @left
    @right.each_node(&block) if @right
  end

  def method_missing(method_name, *args)
    method_name = method_name.to_s
    path = method_name.scan(/(left|right)/).flatten
    current_node = self
    path.each do |direction|
      if direction == "left"
        current_node = current_node.left
      elsif direction == "right"
        current_node = current_node.right
      end
      return nil if current_node.nil?
    end
    return current_node.value
    super
  end
end

my_tree = Tree.new(42,
                   Tree.new(3,
                            Tree.new(1,
                                     Tree.new(7,
                                              Tree.new(22),
                                              Tree.new(123)),
                                     Tree.new(32))),
                   Tree.new(99,
                            Tree.new(81)))

my_tree.each_node do |v|
  puts v
end

arr = []
my_tree.each_node do |v|
  arr.push v
end
p arr

p "Getting nodes from tree"
p my_tree.left_left
p my_tree.right_left
p my_tree.left_left_right
p my_tree.left_left_left_right