#### Roman Numerals

p
```ROMAN = [
(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"),
]

def roman_to_int(roman: str) -> int:
"""
LeetCode No. 13 Roman to Integer
Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.
https://en.wikipedia.org/wiki/Roman_numerals
>>> tests = {"III": 3, "CLIV": 154, "MIX": 1009, "MMD": 2500, "MMMCMXCIX": 3999}
>>> all(roman_to_int(key) == value for key, value in tests.items())
True
"""
vals = {"I": 1, "V": 5, "X": 10, "L": 50, "C": 100, "D": 500, "M": 1000}
total = 0
place = 0
while place < len(roman):
if (place + 1 < len(roman)) and (vals[roman[place]] < vals[roman[place + 1]]):
total += vals[roman[place + 1]] - vals[roman[place]]
place += 2
else:
total += vals[roman[place]]
place += 1

def int_to_roman(number: int) -> str:
"""
Given a integer, convert it to an roman numeral.
https://en.wikipedia.org/wiki/Roman_numerals
>>> tests = {"III": 3, "CLIV": 154, "MIX": 1009, "MMD": 2500, "MMMCMXCIX": 3999}
>>> all(int_to_roman(value) == key for key, value in tests.items())
True
"""
result = []
for arabic, roman in ROMAN:
(factor, number) = divmod(number, arabic)
result.append(roman * factor)
if number == 0:
break
return "".join(result)

if __name__ == "__main__":
import doctest

doctest.testmod()
```