adventofcode2021/aoc6-1.py

class Lanternfish:
    def __init__(self, count=None):
        self.count = 8 if count == None else count

    def age(self):
        self.count -= 1
        if self.count == -1:
            self.count = 6
            return True
        return False

def main():
    num_days = 80

    with open("aoc6-1.txt", "r") as file:
        fish_ages = [int(age) for age in file.readlines()[0].split(",")]
    fishes = []
    for age in fish_ages:
        fishes.append(Lanternfish(age))

    fish_benchmark, fish_increment = 10000, 10000
    for day in range(num_days):
        num_fish = len(fishes)
        if num_fish > fish_benchmark:
            print(f"Reached {num_fish} lanternfish on day {day}.")
            fish_benchmark += fish_increment
        for i in range(num_fish):
            if fishes[i].age():
                fishes.append(Lanternfish())

    print(len(fishes))
    return len(fishes)


if __name__ == "__main__":
    main()