/
huff.rb
82 lines (70 loc) · 2.11 KB
/
huff.rb
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class Node
attr_accessor :left, :right, :value
include Enumerable
@@all = []
@@str = ""
def each(&block)
left.each(&block) if left
block.call(self)
right.each(&block) if right
end
def self.root
@@root
end
def self.str
@@str
end
def self.all
@@all
end
def self.visualize(node, newline, buffer="")
newline ? @@str += " #{node.value}\n" : @@str += "#{node.value} "
@@str += buffer
self.visualize(node.left, false) if node.left
self.visualize(node.right, true, " ") if node.right
# @@buffer = " "
# newline ? @@str += " #{node.value}\n" : @@str += "#{node.value} "
# if pos == :center
# self.visualize(node.left, false, :left) if node.left
# self.visualize(node.right, true, :right) if node.right
# elsif pos == :right
# @@buffer += " "
# @@str.ljust(1, @@buffer)
# self.visualize(node.left, false, :left) if node.left
# self.visualize(node.right, true, :right) if node.right
# elsif pos == :left
# @@buffer += " "
# @@str.rjust(1, @@buffer)
# self.visualize(node.left, false, :left) if node.left
# self.visualize(node.right, true, :right) if node.right
# end
end
def initialize(value, left = nil, right = nil)
@value, @left, @right = value, left, right
@@all << self
end
def self.huffman(string)
self.sort_string(string)
end
def self.sort_string(string)
dict = Hash.new(0)
string.split("").inject(dict) {|_, c| dict[c] += 1 }
sorted_chars = dict.sort_by { |_, v| v }.map { |c, _| c }.reverse
self.populate_tree sorted_chars
end
def self.populate_tree(chars)
root_value = chars.join("")
until @@all.max_by { |n| n.value.length.to_s == (chars.length - 1) }
left = Node.new chars.pop
right = Node.new chars.pop
Node.new(left.value + right.value, left, right)
end
root_right = @@all.max_by { |n| n.value.length.to_s }
root_left = Node.new(chars.pop)
@@root = Node.new(root_value, root_left, root_right)
end
end
Node.huffman "aaaabbcddd"
Node.visualize(Node.root, true)
puts Node.str
puts Node.all.map {|n| n.value}