112 lines
3.3 KiB
Python
112 lines
3.3 KiB
Python
from typing import List, Tuple
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EXAMPLE = """
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MMMSXXMASM
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MSAMXMSMSA
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AMXSXMAAMM
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MSAMASMSMX
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XMASAMXAMM
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XXAMMXXAMA
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SMSMSASXSS
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SAXAMASAAA
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MAMMMXMMMM
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MXMXAXMASX
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"""
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class FindXMAS:
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def __init__(self, input: str) -> None:
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self.input = input
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self.inputgrid = self._to_grid(self.input)
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def __str__(self) -> str:
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return f"Part1: {self._part1}\nPart2: {self._part2}"
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@property
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def _part1(self) -> int:
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return len(self.locate_xmas())
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@property
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def _part2(self) -> int:
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return len(self.locate_x_mas()) // 2
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@staticmethod
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def _to_grid(input: str) -> List[List[str]]:
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return [list(line) for line in input.splitlines() if line]
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def find_neighbours(
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self,
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origin: Tuple[int, int],
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target: str = "XMAS",
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) -> List[Tuple[Tuple[int, ...]]]:
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locations: List[Tuple[Tuple[int, ...]]] = []
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x, y = origin
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if self.inputgrid[x][y].upper() != target[0].upper():
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return []
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for dx in range(-1, 2):
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for dy in range(-1, 2):
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if dx == 0 and dy == 0:
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continue
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current = [(x, y)]
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for n in range(1, len(target)):
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nx = x + (n * dx)
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ny = y + (n * dy)
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if nx < 0 or ny < 0:
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continue
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try:
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if self.inputgrid[nx][ny].upper() == target[n].upper():
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current.append((nx, ny))
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except IndexError:
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pass
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if len(current) == len(target):
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locations.append(tuple(current))
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return locations
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def locate_xmas(self) -> List[Tuple[Tuple[int, ...]]]:
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locations: List[Tuple[Tuple[int, ...]]] = []
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for i, line in enumerate(self.inputgrid):
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for j, char in enumerate(line):
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if char.upper() == "X":
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neighbours = self.find_neighbours((i, j), target="XMAS")
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if neighbours is None:
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continue
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locations = [*locations, *neighbours]
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return locations
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def locate_x_mas(self) -> List[Tuple[Tuple[int, ...]]]:
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mas: List[Tuple[Tuple[int, ...]]] = []
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for i, line in enumerate(self.inputgrid):
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for j, char in enumerate(line):
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if char.upper() == "M":
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neighbours = [
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val
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for val in self.find_neighbours((i, j), target="MAS")
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if all([len(set(part)) == len("MAS") for part in zip(*val)])
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]
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if neighbours is None:
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continue
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mas = [*mas, *neighbours]
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locations: List[Tuple[Tuple[int, ...]]] = []
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# breakpoint()
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for loc in mas:
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oth = [val[1] for val in mas if val != loc and val[::-1] != loc]
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# breakpoint()
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if loc[1] in oth:
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locations.append(loc)
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return locations
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if __name__ == "__main__":
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example = FindXMAS(EXAMPLE)
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print(example)
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assert example._part1 == 18
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assert example._part2 == 9
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with open("input.txt", "r") as f:
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puzzle = FindXMAS(f.read())
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print(puzzle)
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