Ruby Binary Tree Print.. can also be modified to print more

Ruby Binary Tree Print.rb

class BinTree
  class Node
    attr_accessor :data, :left, :right

    def initialize int
      @data = int
    end

    def to_s
      "Node: #{object_id}: data: #{data}"
      "Node: #{data}"
    end
  end

  attr_accessor :root

  def initialize
    @root = nil
  end

  def insert_level_order ary
    i=0
    n=ary.size
    @root = level_order_insert_util ary, i, n
  end

  private
  def level_order_insert_util ary, i, n
    if i<n
      node = Node.new ary[i]
      node.left = level_order_insert_util ary, (2*i)+1, n
      node.right = level_order_insert_util ary, (2*i)+2, n
      node
    else
      # recursion base case: dont run for out of bound nodes
      # puts "#{i}, #{n}"
    end
  end
  
end

class BinTree
  TAIL_STR = "└─"
  FORK_STR = "├─"
  PAD_STR = "│ "
  INDENT_STR = "  "

  def show_tree
    str_builder = []
    walk_tree_str @root, true, "", str_builder
    puts "\n#{str_builder.join("\n")}\n"
  end

  private
  def walk_tree_str node, is_tail_node, prefix, str_builder
    str_builder << "#{prefix} #{is_tail_node ? TAIL_STR : FORK_STR} #{node}"
    child_prefix_str = "#{prefix} #{is_tail_node ? INDENT_STR : PAD_STR}"
    if node.left and node.right
      walk_tree_str node.left, false, "#{child_prefix_str} L", str_builder
      walk_tree_str node.right, true, "#{child_prefix_str} R", str_builder
    else
      walk_tree_str node.left, true, "#{child_prefix_str} L", str_builder if node.left
      walk_tree_str node.right, true, "#{child_prefix_str} R", str_builder if node.right
    end
  end

  
end