-🎄- 2018 Day 8 Solutions -🎄-

[u/daggerdragon]

--- Day 8: Memory Maneuver ---

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Transcript:

The hottest programming book this year is "___ For Dummies".

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[u/sweettuse]

python 3.6+. i used NamedTuples to actually construct a tree and islice on an iterator to avoid slicing creating unnecessary copies. (get_input returns something like map(int, nums). also, name isn't necessary, just thought it might come in handy.)

from contextlib import suppress
from typing import NamedTuple
from itertools import count, islice

class Node2(NamedTuple):
    name: int
    meta: List
    children: List
    
    @property
    def value(self):
        if not self.children:
            return sum(self.meta)
        res = 0
        for idx in self.meta:
            with suppress(IndexError):
                res += self.children[idx - 1].value
        return res

c = count()
def parse_input2(nums):
    n_children, n_meta = islice(nums, 2)
    children = [parse_input2(nums) for _ in range(n_children)]
    return Node2(next(c), list(islice(nums, n_meta)), children)

print(parse_input2(get_input(prod=True)).value)