Advent of Code 2022 day 11

From this day onwards I was otherwise engaged. All following solutions were done roughly a month later in January once the bulk of the holiday mayhem had subsided.

eval behaved bizarrely in previous iterations on this code. I thought brute-forcing part 2 might work, but my patience wore out, and using the lowest common multiple did the trick.

Is there a more sane way to multiple all the elements of an array? There’s probably a function called product or something. Anyway, reduce worked. 

from functools import reduce

# with open("11_test.txt") as f:
with open("11.txt") as f:
    text = f.read()

monkeys = []

class Monkey:
    def __init__(self, data):
        self.number = int(
            data.split("\n")[0].split("Monkey ")[1].split(":")[0]
        )
        self.worry_levels = [
            int(x) for x in data.split("\n")[1].split("items: ")[1].split(", ")
        ]
        self.operations = data.split("\n")[2].split("Operation: new = ")[1]
        self.test = int(data.split("\n")[3].split("divisible by ")[1])
        self.true = int(data.split("\n")[4].split("monkey ")[1])
        self.false = int(data.split("\n")[5].split("monkey ")[1])
        self.inspected = 0

    def __str__(self):
        return (
            str(self.number) +
            ": " +
            ", ".join([str(i) for i in self.worry_levels])
        )

    def turn(self, divisor=None):
        operation = lambda old: eval(self.operations)
        for worry in self.worry_levels:
            if divisor is None:
                new = int(operation(worry)//3)
            else:
                new = operation(worry) % divisor
            if new % self.test == 0:
                monkeys[self.true].worry_levels.append(new)
            else:
                monkeys[self.false].worry_levels.append(new)
            self.inspected += 1
        self.worry_levels = []

for data in text.split("\n\n"):
    monkeys.append(Monkey(data))

for _ in range(20):
    for monkey in monkeys:
        monkey.turn()

print(
    reduce(
        lambda x, y: x*y, sorted([monkey.inspected for monkey in monkeys])[-2:]
    )
)

# Part 2
divisor = reduce(lambda x, y: x*y, (monkey.test for monkey in monkeys))

monkeys = []

for data in text.split("\n\n"):
    monkeys.append(Monkey(data))

for _ in range(10000):
    for monkey in monkeys:
        monkey.turn(divisor=divisor)

print(
    reduce(
        lambda x, y: x*y,
        sorted([monkey.inspected for monkey in monkeys])[-2:]
    )
)

Christian Christiansen.