AOC 2023, day 15

aoc2023_day15.py

import math
from functools import reduce
from itertools import count, repeat

def reindeer(s):
    return reduce(lambda i,c: (17*(i+ord(c)))%256, s, 0)

# Solution, part 1:
sum(map(reindeer, inp.split(",")))

boxes = [{} for _ in range(256)]
for cmd in inp.split(","):
    if cmd.endswith("-"):
        idx = reindeer((label := cmd[:-1]))
        boxes[idx].pop(label, None)
    else:
        label, fc = cmd.split("=")
        boxes[reindeer(label)][label] = int(fc)
        
# Solution, part 2:
sum(sum(map(math.prod, zip(boxes[i].values(), count(1), repeat(i+1)))) for i, b in enumerate(boxes))

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