Calculate the aronson numbers

aronson.rb

# Works from 1 - 999
# Recursively convert to cardinal numbers
def cardinal(num)
  case num
    when 0  then return ""
    when 1  then return "one"
    when 2  then return "two"
    when 3  then return "three"
    when 4  then return "four"
    when 5  then return "five"
    when 6  then return "six"
    when 7  then return "seven"
    when 8  then return "eight"
    when 9  then return "nine"
    when 10 then return "ten"
    when 11 then return "eleven"
    when 12 then return "twelve"
    when 13 then return "thirteen"
    when 14 then return "fourteen"
    when 15 then return "fifteen"
    when 16 then return "sixteen"
    when 17 then return "seventeen"
    when 18 then return "eighteen"
    when 19 then return "nineteen"
  end
    
  return "twenty"   + cardinal(num-20) if (num < 30)
  return "thirty"   + cardinal(num-30) if (num < 40)
  return "forty"    + cardinal(num-40) if (num < 50)
  return "fifty"    + cardinal(num-50) if (num < 60)
  return "sixty"    + cardinal(num-60) if (num < 70)
  return "seventy"  + cardinal(num-70) if (num < 80)
  return "eighty"   + cardinal(num-80) if (num < 90)
  return "ninety"   + cardinal(num-90) if (num < 100)
    
  return cardinal(num/100) + "hundred" + cardinal(num%100)
end

# Works from 1 - 999999
# Recursively convert to ordinal numbers
def ordinal(num)
  case num
		when 0  then return ""
		when 1  then return "first"
		when 2  then return "second"
		when 3  then return "third"
		when 4  then return "fourth"
		when 5  then return "fifth"
		when 6  then return "sixth"
		when 7  then return "seventh"
		when 8  then return "eighth"
		when 9  then return "ninth"
		when 10 then return "tenth"
		when 11 then return "eleventh"
		when 12 then return "twelfth"
		when 13 then return "thirteenth"
		when 14 then return "fourteenth"
		when 15 then return "fifteenth"
		when 16 then return "sixteenth"
		when 17 then return "seventeenth"
		when 18 then return "eighteenth"
		when 19 then return "nineteenth"
		when 20 then return "twentieth"
		when 30 then return "thirtieth"
		when 40 then return "fortieth"
		when 50 then return "fiftieth"
		when 60 then return "sixtieth"
		when 70 then return "seventieth"
		when 80 then return "eightieth"
		when 90 then return "ninetieth"
  end
    
  return cardinal(20) + ordinal(num-20) if (num < 30)
  return cardinal(30) + ordinal(num-30) if (num < 40)
  return cardinal(40) + ordinal(num-40) if (num < 50)
  return cardinal(50) + ordinal(num-50) if (num < 60)
  return cardinal(60) + ordinal(num-60) if (num < 70)
  return cardinal(70) + ordinal(num-70) if (num < 80)
  return cardinal(80) + ordinal(num-80) if (num < 90)
  return cardinal(90) + ordinal(num-90) if (num < 100)

  return cardinal(num/100) + "hundredth" if (num < 1000) and (num % 100 == 0)
  return cardinal(num/100) + "hundred" + ordinal(num%100) if (num < 1000)
  
  return cardinal(num/1000) + "thousandth" if (num % 1000 == 0)
  return cardinal(num/1000) + "thousand" + ordinal(num%1000)
end

#862623
MAX = 100000
		
# Store all aronsons in an array
aronsons = []
index = 0

# Start the sentence
sentence = "tisthe"
#sentence = File.read("cached_aronson_sentence.txt")

# Calculate all the aronson numbers
MAX.times do
  index = sentence.index(?t, index) + 1
  
  sentence << ordinal(index) unless sentence.length > 1000000
  
  aronsons << index
end

#puts sentence
puts aronsons[MAX-1]