64 lines
2.3 KiB
Python
64 lines
2.3 KiB
Python
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# SPDX-License-Identifier: MIT
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# Copyright (c) 2021 Akumatic
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#
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# https://adventofcode.com/2021/day/22
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from collections import defaultdict
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def parse_line(line: str) -> str:
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state = True if line.startswith("on") else False
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coords = line[3 if state else 4:].split(",")
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return [state] + [(int(p[0]), int(p[1])) for p in (pos[2:].split("..") for pos in coords)]
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def read_file(filename: str = "input.txt") -> defaultdict:
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with open(f"{__file__.rstrip('code.py')}{filename}", "r") as f:
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return [parse_line(line) for line in f.read().strip().split("\n")]
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def areas_overlapping(a: tuple, b: tuple) -> bool:
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return a[0][0] <= b[0][1] and a[0][1] >= b[0][0] \
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and a[1][0] <= b[1][1] and a[1][1] >= b[1][0] \
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and a[2][0] <= b[2][1] and a[2][1] >= b[2][0]
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def calculate_overlap(a: tuple, b: tuple) -> tuple:
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return ((max(a[0][0], b[0][0]), min(a[0][1], b[0][1])),
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(max(a[1][0], b[1][0]), min(a[1][1], b[1][1])),
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(max(a[2][0], b[2][0]), min(a[2][1], b[2][1])))
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def cubes_in_cuboid(cuboid: tuple) -> int:
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return (cuboid[0][1] - cuboid[0][0] + 1) * \
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(cuboid[1][1] - cuboid[1][0] + 1) * (cuboid[2][1] - cuboid[2][0] + 1)
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def changes_adding_cuboid(cuboids: list, state: bool, cuboid: tuple) -> list:
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changes = []
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signum = 1 if state else -1
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for cub, sig in cuboids:
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if areas_overlapping(cub, cuboid):
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changes.append((calculate_overlap(cub, cuboid), -sig))
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if signum == 1:
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changes.append((cuboid, 1))
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return changes
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def part1(instructions: list) -> int:
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reactor = defaultdict(bool)
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area = ((-50, 50), (-50, 50), (-50, 50))
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for state, x, y, z in instructions:
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cur = (x, y, z)
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if not areas_overlapping(cur, area):
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continue
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a, b, c = calculate_overlap(cur, area)
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cubes = [(u, v, w) for u in range(a[0], a[1]+1) for v in range(b[0], b[1]+1) for w in range(c[0], c[1]+1)]
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for cube in cubes:
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reactor[cube] = state
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return sum(reactor.values())
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def part2(instructions: list) -> int:
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cuboids = list()
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for state, x, y, z in instructions:
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cuboids += changes_adding_cuboid(cuboids, state, (x, y, z))
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return sum(cubes_in_cuboid(cub) * sig for cub, sig in cuboids)
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if __name__ == "__main__":
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vals = read_file()
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print(f"Part 1: {part1(vals)}")
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print(f"Part 2: {part2(vals)}")
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