def __add__(self, other): num1 = exploderise(self.num) num2 = exploderise(other.num) combination = num1 + num2 reversed_sorted_combination = sort_num(combination, rev=False) combined = combine(reversed_sorted_combination) combined[::-1] return RomanNumeral(compressurise(combined))
def __sub__(self, other):
num1 = exploderise(self.num)
num2 = exploderise(other.num)
c = Counter(num1)
c.subtract(Counter(num2))
letters = sorted(values.keys(), key=sorter)
for i, l in enumerate(letters):
if c[l] < 0:
if l == 'V':
c.subtract(Counter({l:-2, letters[i+1]:1}))
else:
c.subtract(Counter({l:-5, letters[i+1]:1}))
expanded_number = sort_num(c.elements())
corrected_number = compressurise(combine(expanded_number))
return RomanNumeral(corrected_number)
