62 lines
1.5 KiB
Python
Executable file
62 lines
1.5 KiB
Python
Executable file
#!/usr/bin/env python
|
|
|
|
import dataclasses
|
|
import functools
|
|
import operator
|
|
import sys
|
|
from collections import Counter
|
|
from typing import NamedTuple
|
|
|
|
|
|
class Point(NamedTuple):
|
|
x: int
|
|
y: int
|
|
|
|
|
|
@dataclasses.dataclass
|
|
class Robot:
|
|
pos: Point
|
|
vel: Point
|
|
|
|
def step(self, dims: Point, delta: int = 1) -> "Robot":
|
|
x, y = self.pos.x + self.vel.x * delta, self.pos.y + self.vel.y * delta
|
|
return Robot(
|
|
Point(x % dims.x, y % dims.y),
|
|
self.vel,
|
|
)
|
|
|
|
|
|
def solve(input: str) -> int:
|
|
def parse_robot(input: str) -> Robot:
|
|
pos, vel = map(lambda s: s.split("=")[1], input.split(" "))
|
|
return Robot(
|
|
Point(*map(int, pos.split(","))),
|
|
Point(*map(int, vel.split(","))),
|
|
)
|
|
|
|
def parse(input: list[str]) -> list[Robot]:
|
|
return [parse_robot(line) for line in input]
|
|
|
|
def compute_safety(robots: list[Robot], dims: Point) -> int:
|
|
mid_x, mid_y = dims.x // 2, dims.y // 2
|
|
counts: Counter[tuple[bool, bool]] = Counter()
|
|
for x, y in map(lambda robot: robot.pos, robots):
|
|
if x == mid_x or y == mid_y:
|
|
continue
|
|
counts[(x < mid_x, y < mid_y)] += 1
|
|
return functools.reduce(operator.mul, counts.values())
|
|
|
|
robots = parse(input.splitlines())
|
|
dims = Point(101, 103)
|
|
robots = [robot.step(dims, 100) for robot in robots]
|
|
return compute_safety(robots, dims)
|
|
|
|
|
|
def main() -> None:
|
|
input = sys.stdin.read()
|
|
print(solve(input))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|