int romanToInt(char* s) {

    int vals['X'+1];
    int cur = 0;
    int next = 0;
    int ret = 0;

    vals[0]   = 0;
    vals['I'] = 1;
    vals['V'] = 5;
    vals['X'] = 10;
    vals['L'] = 50;
    vals['C'] = 100;
    vals['D'] = 500;
    vals['M'] = 1000;

    for (int i = 0; s[i]; i++) {
        cur = vals[s[i]];
        next = vals[s[i+1]];
        if (cur < next) {
            ret -= cur;
        }
        else {
            ret += cur;
        }
    }
    return ret;

}