51 lines
1.4 KiB
Python
51 lines
1.4 KiB
Python
from os.path import join, dirname
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from typing import List, Optional, Set, Tuple
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from itertools import combinations
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class XMAS:
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def __init__(self, data: str, size: int) -> None:
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self.size: int = size
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self.position: int = size
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self.buffer: List[int] = [
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int(x)
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for x in data.strip().split('\n')
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]
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def check_next(self) -> bool:
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possible = [
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a + b
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for a, b in combinations(self.buffer[self.position - self.size: self.position], 2)
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]
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return self.buffer[self.position] in possible
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def find_first_invalid(self) -> int:
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l = len(self.buffer)
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while self.position < l:
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valid = self.check_next()
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if not valid:
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return self.buffer[self.position]
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self.position += 1
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raise Exception
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def find_slice(self, target: int):
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l = len(self.buffer)
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for n in range(l):
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for m in range(n, l):
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slice = self.buffer[n: m]
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if sum(slice) == target:
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return min(slice) + max(slice)
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raise Exception
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data = join(dirname(__file__), '../data.txt')
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with open(data) as f:
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xmas = XMAS(f.read(), 25)
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first_invalid = xmas.find_first_invalid()
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print(first_invalid)
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solution = xmas.find_slice(first_invalid)
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print(solution)
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