import re
import pytest
def romanToInt(s:str):
    special = {'IV': 4,
                'IX': 9,
                'XL': 40,
                'XC': 90,
                'CD': 400,
                'CM': 900}
    single = {'I': 1,
              'V': 5,
              'X': 10,
              'L': 50,
              'C': 100,
              'D': 500,
              'M': 1000}

    r = 0
    for k, v in special.items():
        if k in s:
            r += v
            s = re.sub(k, '', s)
            print(s)

    for i in s:
        r += single[i]

    return r


@pytest.mark.parametrize(
    "s, expect",
    [
        ('IV', 4),
        ('III', 3),
        ('LVIII', 58),
        ('MCMXCIV', 1994)
    ]
)
def test_cases(s, expect):
    assert romanToInt(s) == expect