Binary tree with some boundary rules

gistfile1.rb

require 'rubygems'
require 'graphviz'

@min_level = 1
@max_level = 12
@max_depth = 10
start_level = 6

@g = GraphViz.new(:G, :type => "strict digraph" )

def add_node(level, depth, parent)
  if depth < @max_depth
    current = [level, depth].join(",")

    sub = level <=> @min_level
    add = @max_level <=> level
    add_node(level - sub, depth + 1, current)
    add_node(level + add, depth + 1, current)

    @g.add_node(current).label = level.to_s
    @g.add_edge(parent, current) unless parent == "00"
  end
end

add_node(start_level, 0, "00")

@g.output( :png => "/www/pages/g.png" ) # http://plea.se/g.png