Use C to complete the task of converting Roman numerals to Arabic numerals
int romanToInt(char * s){
int symbolValues[26];
symbolValues['I' - 'A'] = 1;
symbolValues['V' - 'A'] = 5;
symbolValues['X' - 'A'] = 10;
symbolValues['L' - 'A'] = 50;
symbolValues['C' - 'A'] = 100;
symbolValues['D' - 'A'] = 500;
symbolValues['M' - 'A'] = 1000;
int ans = 0;
int n = strlen(s);
for (int i = 0; i < n; ++i) {
int value = symbolValues[s[i] - 'A'];
if (i < n - 1 && value < symbolValues[s[i + 1] - 'A']) {
ans -= value;
} else {
ans += value;
}
}
return ans;
}