Comparative linguistics

class Solution:def romanToInt(self, s: str) -> int:d = {"I": 1,"V": 5,"X": 10,"L": 50,"C": 100,"D": 500,"M": 1000,}ret = 0i = 0while i < len(s) -1:if (d[s[i]] < d[s[i+1]]):ret -= d[s[i]]else:ret += d[s[i]]i+=1return ret + d[s[i]]

int hash(char c)
{switch(c){case 'I':return 1;break;case 'V':            return 5;break;        case 'X':return 10;break;        case 'L':return 50;break;        case 'C':return 100;break;        case 'D':return 500;break;        case 'M':return 1000;break;        default:break;}return 0;
}int romanToInt(char* s) {int ret = 0;for (int i = 0; i < strlen(s);){if (hash(s[i]) < hash(s[i+1])){ret += (hash(s[i+1]) - hash(s[i]));i+=2;}else {ret += hash(s[i]);i++;}}return ret;
}

all 100%.

1. C has no hashtable, so I used switch, which actually hash('\0') as 0.
2. len(s) and strlen(s) in Python and C all got a 3.
   but in python:

>>> s = "abc"
>>> s[3]
Traceback (most recent call last):File "<stdin>", line 1, in <module>
IndexError: string index out of range

printf("%d\n%d", strlen(s), s[4]);

in C, s[3] will printf 0 as %d, and s[4] could be anything but it's accessable. such as 37, whatever.

so in C, I actually access the last char of s as '\0'. But in python, the operator is not safe. but there's also no char type in python.