roman_numerals.rb

def to_roman(num)
  str = ''
  # Your code here
  if num >= 1000
    str += 'M' * (num / 1000)
    num %= 1000
  end
  
  if num == 900
    str += 'CM'
    num -= 900
  end
  
  if num >= 500
    str += 'D'
    num -= 500
  end
  
  if num >= 400
    str += 'CD'
    num -= 400
  end
  
  if num >= 100
    str += 'C' * (num / 100)
    num %= 100
  end
  
  if num >= 90
    str += 'CX'
    num -= 90
  end
  
  if num >= 50
    str += 'L'
    num -= 50
  end
  
  if num >= 40
    str += 'XL'
    num -= 40
  end
    
  if num >= 10
    str += 'X' * (num / 10)
    num %= 10
  end
  
  if num == 9
    str += 'IX'
    num -= 9
  end
  
  if num >= 5
    str += 'V'
    num -= 5
  end
  
  if num == 4
    str += 'IV'
  else
    str + ('I' * num)
  end
end


# Drive code... this should print out trues.

puts to_roman(1) == "I"
puts to_roman(3) == "III"
puts to_roman(6) == "VI"
puts to_roman(4) == "IV"
puts to_roman(9) == "IX"
puts to_roman(14) == "XIV"
puts to_roman(44) == "XLIV"
puts to_roman(944) == "CMXLIV"

# TODO: what other cases could you add to ensure your to_roman method is working?

roman_numerals2.rb

def to_roman(num)
  roman = %w(M CM D CD C CX L XL X IX V IV I)
  numerals = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
  str = ''

  for i in 0..(roman.length - 1)
    if num >= numerals[i]
      str += roman[i] * (num / numerals[i])
      num %= numerals[i]
    end
  end
  str
end


# Drive code... this should print out trues.

puts to_roman(1) == "I"
puts to_roman(3) == "III"
puts to_roman(6) == "VI"
puts to_roman(4) == "IV"
puts to_roman(9) == "IX"
puts to_roman(14) == "XIV"
puts to_roman(44) == "XLIV"
puts to_roman(944) == "CMXLIV"

# TODO: what other cases could you add to ensure your to_roman method is working?

roman_numerals3.rb

def to_roman(num)
  
  romans = {"M"=>1000, "CM"=>900, "D"=>500, "CD"=>400, "C"=>100, "CX"=>90, "L"=>50, "XL"=>40, "X"=>10, "IX"=>9, "V"=>5, "IV"=>4, "I"=>1}
  str = ''

  romans.each do |roman, digit|
    if num >= digit
      str += roman * (num / digit)
      num %= digit
    end
  end
  str
end


# Drive code... this should print out trues.

puts to_roman(1) == "I"
puts to_roman(3) == "III"
puts to_roman(6) == "VI"
puts to_roman(4) == "IV"
puts to_roman(9) == "IX"
puts to_roman(14) == "XIV"
puts to_roman(44) == "XLIV"
puts to_roman(944) == "CMXLIV"

# TODO: what other cases could you add to ensure your to_roman method is working?