diff --git a/strings/integer_to_roman.py b/strings/integer_to_roman.py new file mode 100644 index 000000000000..91efbe6dbda2 --- /dev/null +++ b/strings/integer_to_roman.py @@ -0,0 +1,52 @@ +def integer_to_roman(number: int) -> str: + """ + Convert an integer to a Roman numeral. + + Examples: + >>> integer_to_roman(1) + 'I' + >>> integer_to_roman(4) + 'IV' + >>> integer_to_roman(9) + 'IX' + >>> integer_to_roman(58) + 'LVIII' + >>> integer_to_roman(1994) + 'MCMXCIV' + >>> integer_to_roman(0) + Traceback (most recent call last): + ... + ValueError: number must be between 1 and 3999 + """ + if not (1 <= number <= 3999): + raise ValueError("number must be between 1 and 3999") + + symbols = [ + (1000, "M"), + (900, "CM"), + (500, "D"), + (400, "CD"), + (100, "C"), + (90, "XC"), + (50, "L"), + (40, "XL"), + (10, "X"), + (9, "IX"), + (5, "V"), + (4, "IV"), + (1, "I"), + ] + + result = [] + for value, numeral in symbols: + while number >= value: + result.append(numeral) + number -= value + + return "".join(result) + + +if __name__ == "__main__": + import doctest + + doctest.testmod()