Problem17.rb

def englishNumber number
  if number < 0  #  No negative numbers.
    return 'Please enter a number that isn\'t negative.'
  end
  if number == 0
    return 'zero'
  end
  
  #  No more special cases!  No more returns!
  
  numString = ''  #  This is the string we will return.
  
  onesPlace = ['one',     'two',       'three',    'four',     'five',
               'six',     'seven',     'eight',    'nine']
  tensPlace = ['ten',     'twenty',    'thirty',   'forty',    'fifty',
               'sixty',   'seventy',   'eighty',   'ninety']
  teenagers = ['eleven',  'twelve',    'thirteen', 'fourteen', 'fifteen',
               'sixteen', 'seventeen', 'eighteen', 'nineteen']
  
  #  "left" is how much of the number we still have left to write out.
  #  "write" is the part we are writing out right now.
  #  write and left... get it?  :)
  left  = number

  
  #thousands start
    write = left/1000		# How many thousands left to write out?
    left = left - write*1000	# Subtract off those thousands.

    if write > 0
  	thousands = englishNumber write
  	numString = numString + thousands + ' thousand'

      if left > 0
        #  So we don't write 'two thousandthreehundred-fiftyone'...
        numString = numString + ' '
      end
    end
  #thousands end

  #hundreds start
    write = left/100          #  How many hundreds left to write out?
    left  = left - write*100  #  Subtract off those hundreds.
  
    if write > 0
      #  Now here's a really sly trick:
      hundreds  = englishNumber write
      numString = numString + hundreds + ' hundred'
      #  That's called "recursion".  So what did I just do?
      #  I told this method to call itself, but with "write" instead of
      #  "number".  Remember that "write" is (at the moment) the number of
      #  hundreds we have to write out.  After we add "hundreds" to "numString",
      #  we add the string ' hundred' after it.  So, for example, if
      #  we originally called englishNumber with 1999 (so "number" = 1999),
      #  then at this point "write" would be 19, and "left" would be 99.
      #  The laziest thing to do at this point is to have englishNumber
      #  write out the 'nineteen' for us, then we write out ' hundred',
      #  and then the rest of englishNumber writes out 'ninety-nine'.
    
      if left > 0
        #  So we don't write 'two hundredfifty-one'...
        numString = numString + " and "
      end
    end
    # hundreds end
    
    # tens start
    write = left/10          #  How many tens left to write out?
    left  = left - write*10  #  Subtract off those tens.
  
    if write > 0
      if ((write == 1) and (left > 0))
        #  Since we can't write "tenty-two" instead of "twelve",
        #  we have to make a special exception for these.
        numString = numString + teenagers[left-1]
        #  The "-1" is because teenagers[3] is 'fourteen', not 'thirteen'.
      
        #  Since we took care of the digit in the ones place already,
        #  we have nothing left to write.
        left = 0
      else
        numString = numString + tensPlace[write-1]
        #  The "-1" is because tensPlace[3] is 'forty', not 'thirty'.
      end
    
      if left > 0
        #  So we don't write 'sixtyfour'...
        numString = numString + '-'
      end
    end
    #tens end
  
    #ones start
    write = left  #  How many ones left to write out?
    left  = 0     #  Subtract off those ones.
  
    if write > 0
      numString = numString + onesPlace[write-1]
      #  The "-1" is because onesPlace[3] is 'four', not 'three'.
    end
  
    #  Now we just return "numString"...
    numString
  end
  #ones end
  
sum = 0

1.upto(1000) do |i|
  sum += englishNumber(i).tr('-','').tr(' ','').length
end


puts sum