65 lines
2.1 KiB
Python
Executable file
65 lines
2.1 KiB
Python
Executable file
#!/usr/bin/env python
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import itertools
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import sys
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from typing import NamedTuple
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class Machine(NamedTuple):
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lights: tuple[bool, ...]
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buttons: list[list[int]]
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joltage: list[int]
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@classmethod
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def from_str(cls, input: str) -> "Machine":
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raw_lights, *raw_buttons, raw_joltage = input.split()
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lights = [c == "#" for c in raw_lights[1:-1]]
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buttons = [[int(n) for n in button[1:-1].split(",")] for button in raw_buttons]
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joltage = [int(n) for n in raw_joltage[1:-1].split(",")]
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return cls(tuple(lights), buttons, joltage)
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def solve(input: list[str]) -> int:
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def parse(input: list[str]) -> list[Machine]:
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return [Machine.from_str(line) for line in input]
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def apply_schematic(
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lights: tuple[bool, ...],
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button: list[int],
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) -> tuple[bool, ...]:
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assert all(n < len(lights) for n in button) # Sanity check
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return tuple((l if i not in button else not l) for i, l in enumerate(lights))
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def start_presses(machine: Machine) -> int:
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start = tuple(False for _ in machine.lights)
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queue = [start]
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seen = {start}
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for i in itertools.count(1):
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new_queue: list[tuple[bool, ...]] = []
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for p in queue:
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for button in machine.buttons:
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n = apply_schematic(p, button)
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# If we've seen `n` before, it was in less or equal number of steps
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if n in seen:
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continue
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# If we're at the end state, we've found the fastest path
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if n == machine.lights:
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return i
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# Else, explore from that state
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new_queue.append(n)
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seen.add(n)
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assert new_queue # Sanity check
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queue = new_queue
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assert False # Sanity check
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manual = parse(input)
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return sum(start_presses(machine) for machine in manual)
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def main() -> None:
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input = sys.stdin.read().splitlines()
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print(solve(input))
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if __name__ == "__main__":
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main()
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