Day 6

6.py

@@ -0,0 +1,56 @@
+from argparse import ArgumentParser
+from collections import defaultdict
+
+NEW_FISH = 8
+RELOAD_FISH = 6
+
+
+def simulate_slow(days):
+    fishes = [int(x) for x in input().split(",")]
+
+    for _ in range(days):
+        new_fish = []
+        for i, _ in enumerate(fishes):
+            fishes[i] -= 1
+            if fishes[i] == -1:
+                fishes[i] = RELOAD_FISH
+                new_fish.append(NEW_FISH)
+        fishes += new_fish
+
+    return len(fishes)
+
+
+def simulate(days):
+    fishes_list = [int(x) for x in input().split(",")]
+    fishes: defaultdict[int, int] = defaultdict(int)
+
+    for fish in fishes_list:
+        fishes[fish] += 1
+
+    for _ in range(days):
+        next = defaultdict(int)
+
+        for timer, n in fishes.items():
+            if timer == 0:
+                next[NEW_FISH] += n
+                next[RELOAD_FISH] += n
+            else:
+                next[timer - 1] += n
+
+        fishes = next
+
+    return sum(fishes.values())
+
+
+if __name__ == "__main__":
+    parser = ArgumentParser()
+    parser.add_argument("days", nargs="?", default=80, type=int)
+    parser.add_argument("--slow", "-s", action="store_true")
+    args = parser.parse_args()
+
+    if args.slow:
+        if args.days > 80:
+            print("Are you sure?")
+        print(simulate_slow(args.days))
+    else:
+        print(simulate(args.days))