advent-of-code-2k21/day6/day6.py
2021-12-10 16:31:23 +01:00

27 lines
721 B
Python

from collections import defaultdict, Counter
def calculate_fishes(inp, days):
fishes = Counter(inp)
for day in range(days):
fishes_new = defaultdict(int)
for fish, cnt in fishes.items():
if fish == 0:
fishes_new[8] += cnt
fishes_new[6] += cnt
else:
fishes_new[fish - 1] += cnt
fishes = fishes_new
return sum(fishes.values())
def main(infile):
with open(infile) as f:
inp = [int(x) for x in f.readline().split(",")]
res = calculate_fishes(inp, 80)
print(f"Part 1, {res}")
res = calculate_fishes(inp, 256)
print(f"Part 2, {res}")
if __name__ == "__main__":
main("input.txt")