Codecery :: Exercise 004

Exercise-004.rb

require 'test/unit'
extend Test::Unit::Assertions

FIRST_TEN = ["zero ", "one ", "two ", "three ", "four ", "five ", "six ", "seven ", "eight ", "nine "] 
SECOND_TEN = ["ten ", "eleven ", "twelve ", "thirteen ", "fourteen ", "fifteen ", "sixteen ", "seventeen ", "eighteen ", "nineteen "]
OTHER_TENS = ["", "", "twenty ", "thirty ", "forty ", "fifty ", "sixty ", "seventy ", "eighty ", "ninety "]
HUNDRED = "hundred "


def number2text(number)
    number_str = number.to_s
	total_dig = number_str.length
	number_letter = ""
	return false if number > 999
	number_letter = FIRST_TEN[0] if number == 0
	if number > 99
		number_letter = FIRST_TEN[(number_str[total_dig-3]).to_i] + HUNDRED
		number = number - (number_str[total_dig-3]+'00').to_i
	end
	if number > 19
		if number % 10 == 0
			number_letter = number_letter + OTHER_TENS[(number_str[total_dig-2]).to_i]
			number = number - (number_str[total_dig-2]+number_str[total_dig-1]).to_i
		else
			number_letter = number_letter + OTHER_TENS[(number_str[total_dig-2]).to_i]
			number = number - (number_str[total_dig-2]+'0').to_i
		end
	end
	if number > 9
		number_letter = number_letter + SECOND_TEN[(number_str[total_dig-1]).to_i]
		number = number - (number_str[total_dig-2]+number_str[total_dig-1]).to_i
	end
	if number > 0
		number_letter = number_letter + FIRST_TEN[(number_str[total_dig-1]).to_i]
		number = number - (number_str[total_dig-1]).to_i
	end
	number_letter.strip()
end

assert number2text(4) == 'four', "First"
assert number2text(133) == 'one hundred thirty three', "Second"
assert number2text(12)=='twelve', "Third"
assert number2text(101)=='one hundred one', "Fifth"
assert number2text(212)=='two hundred twelve', "Sixth"
assert number2text(40)=='forty', "Seventh, forty - it is correct"

puts 'All ok'

puts ''