Day 6

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()

aoc6-2.py

+class LanternfishSchool:
+    def __init__(self, counts, size_inc=100000):
+        self.time_left = {}
+        self.time_left["ttr"] = 0
+        for i in range(9):
+            self.time_left[i] = counts.count(i)
+        self.size_inc = size_inc
+        self.size_base = size_inc
+
+    def age(self):
+        self.time_left["ttr"] = self.time_left[0]
+        for i in range(1,9):
+            self.time_left[i-1] = self.time_left[i]
+        self.time_left[8] = self.time_left["ttr"]
+        self.time_left[6] += self.time_left["ttr"]
+        self.time_left["ttr"] = 0
+        if self.school_size() >= self.size_base:
+            print(f"School size now {self.school_size()}.")
+
+    def school_size(self):
+        total = 0
+        for _,v in self.time_left.items():
+            total += v
+        return total
+
+def main():
+    # The old version gets untenable above about 100 days.
+    # Trying a different approach.
+    num_days = 256
+    with open("aoc6-1.txt", "r") as file:
+        fish_ages = [int(age) for age in file.readlines()[0].split(",")]
+
+    lfs = LanternfishSchool(fish_ages)
+    for _ in range(num_days):
+        lfs.age()
+    print(lfs.school_size())
+
+if __name__ == "__main__":
+    main()