binary_tree.rb

class BinaryTree
  attr_accessor :data, :left, :right

  def initialize(data, left, right)
    @data  = data
    @left  = left
    @right = right
  end

  # Return a new tree with all the nodes reversed.
  #
  # For example, calling this method on a tree that
  # looks like this
  #
  #                    (50)
  #                   /    \
  #                 (20)   (80)
  #                /   \      \
  #              (10)  (30)    (90)
  #                    /  \
  #                  (25) (40)
  #
  # should return a tree that looks like this
  #
  #                    (50)
  #                   /    \
  #                 (80)   (20)
  #                /       /   \
  #              (90)    (30)  (10)
  #                      /  \
  #                    (40) (25)
  #
  # .
  #
  # You are encouraged to use recursion.
  def mirror
  end
end