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 = 0
        i = 0
        while i < len(s) -1:
            if (d[s[i]] < d[s[i+1]]):
                ret -= d[s[i]]
            else:
                ret += d[s[i]]
            i+=1
        return 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.