题目：
题解：
class Solution:SYMBOL_VALUES = {'I': 1,'V': 5,'X': 10,'L': 50,'C': 100,'D': 500,'M': 1000,}def romanToInt(self, s: str) -> int:ans = 0n = len(s)for i, ch in enumerate(s):value = Solution.SYMBOL_VALUES[ch]if i < n - 1 and value < Solution.SYMBOL_VALUES[s[i + 1]]:ans -= valueelse:ans += valuereturn ans
