51 lines
1.3 KiB
Python
51 lines
1.3 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
|
||
|
|
import itertools
|
||
|
|
import sys
|
||
|
|
from collections import defaultdict
|
||
|
|
from typing import NamedTuple
|
||
|
|
|
||
|
|
|
||
|
|
class Point(NamedTuple):
|
||
|
|
x: int
|
||
|
|
y: int
|
||
|
|
|
||
|
|
|
||
|
|
def solve(input: str) -> int:
|
||
|
|
def parse(input: list[str]) -> dict[str, set[Point]]:
|
||
|
|
res: dict[str, set[Point]] = defaultdict(set)
|
||
|
|
for x, line in enumerate(input):
|
||
|
|
for y, c in enumerate(line):
|
||
|
|
if c == ".":
|
||
|
|
continue
|
||
|
|
res[c].add(Point(x, y))
|
||
|
|
return res
|
||
|
|
|
||
|
|
def find_antinodes(grid: dict[str, set[Point]], dims: Point) -> set[Point]:
|
||
|
|
max_x, max_y = dims
|
||
|
|
antinodes: set[Point] = set()
|
||
|
|
for antennas in grid.values():
|
||
|
|
for start, end in itertools.permutations(antennas, 2):
|
||
|
|
dx, dy = end.x - start.x, end.y - start.y
|
||
|
|
x, y = start.x - dx, start.y - dy
|
||
|
|
if not (0 <= x < max_x):
|
||
|
|
continue
|
||
|
|
if not (0 <= y < max_y):
|
||
|
|
continue
|
||
|
|
antinodes.add(Point(x, y))
|
||
|
|
return antinodes
|
||
|
|
|
||
|
|
lines = input.splitlines()
|
||
|
|
max_x, max_y = len(lines), len(lines[0])
|
||
|
|
grid = parse(lines)
|
||
|
|
return len(find_antinodes(grid, Point(max_x, max_y)))
|
||
|
|
|
||
|
|
|
||
|
|
def main() -> None:
|
||
|
|
input = sys.stdin.read()
|
||
|
|
print(solve(input))
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|