Advent of Code 2020

2020_day_18.py

result = 0

def new_calculate(line):
	if '+' not in line and '*' not in line:
		return int(line)
	flatten = ""
	idx = 0
	ctx = 0
	temp = ""
	while len(line) > idx:
		if line[idx] == '(':
			if ctx != 0:
				temp += '('
			ctx += 1
		elif line[idx] == ')':
			ctx -= 1
			if ctx == 0:
				flatten += str(new_calculate(temp))
				temp = ""
			else:
				temp += ')'
		else:
			if ctx == 0:
				flatten += line[idx]
			else:
				temp += line[idx]
		idx += 1
	for c in ('*', '+'):
		left, operator, right = flatten.partition(c)
		if operator == '+':
			return new_calculate(left) + new_calculate(right)
		elif operator == '*':
			return new_calculate(left) * new_calculate(right)


with open('18_input.txt') as f:
	while True:
		line = f.readline()
		if not line or line.rstrip() == "":
			if not line:
				break
			continue
		line = line.rstrip()
		print(line)
		temp = new_calculate(line)
		print(temp)
		result += temp

print(result)