Second challenfe for http://apply.embed.ly

standar_dev.rb

# encoding: UTF-8

def standar_deviation(values)
  total = 0.0
  values.each { |value| total += value }
  average = total / values.length
  total = 0.0
  deviation = values.each { |value|
    total += (value - average) ** 2
  }
  total /= values.length
  return Math.sqrt total
end

def scan_text()
  stack = []
  depth = []
  depths = []
  closing = false
  tag = ""
  i = 0
  file = File.new("step2_input.txt", "r")
  file.each_line { |line|
    line.chars { |c| 
      if c == "<" #starting tag
        stack.push c
      elsif c == ">" #tag ended
        if !closing and tag == "p" #Found new p stack
          depths.push depth.length  #Push the current length to the results
        end
        if closing #end tag, pop from stack to decreased current depth
          depth.pop
          closing = false
        elsif #Push the tag name to the depth stack
          depth.push tag
        end
        tag = ""
        stack.pop
      elsif c == "/" #Closing tag, set closing flag
        if stack.last == "<"
          closing = true
        end
      else #Part of the current stack, build up its name
        if stack.last == "<"
          tag += c
        end
      end
    }
  }
  file.close
  puts standar_deviation depths
end

scan_text