13. Roman to Integer

13. Roman to Integer

int romanToInt(char* s) {
    int dic[26];
    dic['I'-'A'] = 1;
    dic['V'-'A'] = 5;
    dic['X'-'A'] = 10;
    dic['L'-'A'] = 50;
    dic['C'-'A'] = 100;
    dic['D'-'A'] = 500;
    dic['M'-'A'] = 1000;
    int n = 0;
    for(int i = 0;s[i];i++){
        if(s[i+1] && ((s[i] == 'I' && (s[i+1] == 'V' || s[i+1] == 'X'))
                ||(s[i] == 'X' && (s[i+1] == 'L' || s[i+1] == 'C'))
                ||(s[i] == 'C' && (s[i+1] == 'D' || s[i+1] == 'M')))){
            n += dic[s[i+1]-'A'] - dic[s[i]-'A'];
            i++;
        }
        else n += dic[s[i]-'A'];
    }
    return n;
}