module TreePrint

# File lib/tree_print.rb, line 33
def indent(height)
  " " * (1...height).inject { |sum, n| sum + 2 ** (n-1) } rescue ""
end

# File lib/tree_print.rb, line 2
def tree_to_s(*hosts)
  return '' if !hosts.any?
  height = hosts.compact.map(&:height).max
  buffer = indent(height)
  max_length = hosts.compact.map { |node| node.val.to_s.length }.max
  max_length = [8, max_length].min   #arbitrary cut-off for super-long strings
  str = ""
  row = ""
  max_length.times do |i|
    row = hosts.inject("") do |sum, node|
      sum + buffer + (node.val.to_s[i] || '.') + buffer + " " rescue sum + buffer + " " + buffer + " "  #in case node is nil
    end + " \n"
    str << row
  end
  if height > 1
    (2**(height-2)).times do
      row = row.gsub(/ \//, '/ ').gsub(/\\ /, " \\")  #left and right slashes
               .gsub(/ [\w|.] /, '/ \\')              #exchange values for slashes
      str << row
    end
  end
  return str + tree_to_s(*hosts.flat_map{ |host|    #recursion, breadth-first
    if !host
      [nil, nil]
    else
      [host.left, host.right]
    end
  })
end