int add(char *sum, const char *augend, const char *addend) {
if (sum == NULL || augend == NULL || addend == NULL) {
return ROMCALC_NULL_POINTER_ERROR;
}
if (!is_roman_numeral(augend) || !is_roman_numeral(addend)) {
return ROMCALC_INVALID_OPERAND_ERROR;
}
int result = roman_to_arabic(augend) + roman_to_arabic(addend);
if (!is_in_range(result)) {
return ROMCALC_INVALID_RESULT_ERROR;
}
arabic_to_roman(sum, result);
return ROMCALC_SUCCESS;
}
int subtract(char *difference, const char *minuend, const char *subtrahend) {
if (difference == NULL || minuend == NULL || subtrahend == NULL) {
return ROMCALC_NULL_POINTER_ERROR;
}
if (!is_roman_numeral(minuend) || !is_roman_numeral(subtrahend)) {
return ROMCALC_INVALID_OPERAND_ERROR;
}
int result = roman_to_arabic(minuend) - roman_to_arabic(subtrahend);
if (!is_in_range(result)) {
return ROMCALC_INVALID_RESULT_ERROR;
}
arabic_to_roman(difference, result);
return ROMCALC_SUCCESS;
}
int main(void)
{
int cnt = 0;
const char *ptr = roman;
while (*ptr) {
char str[64];
const char *tmp = ptr;
arabic_to_roman(roman_to_arabic(&ptr), str);
cnt += (ptr - tmp) - strlen(str);
ptr++;
}
printf("%d\n", cnt);
return 0;
}