Super messy 2019 day 10

I accidentally inverted my y-axis and I'm not fixing it.

2019/aoc2019/day10.py

@@ -0,0 +1,93 @@
+import math
+from collections import defaultdict
+from typing import TextIO, Tuple
+
+import numpy  # type: ignore
+
+
+def read_asteroids(data: TextIO) -> Tuple[numpy.array, numpy.array]:
+    xs = []
+    ys = []
+    for y, line in enumerate(data):
+        for x, c in enumerate(line):
+            if c == '#':
+                xs.append(x)
+                ys.append(y)
+
+    return numpy.array(xs), -numpy.array(ys)
+
+
+def asteroids_visible(x: int, y: int, xs: numpy.array, ys: numpy.array) -> int:
+    dx = xs - x
+    dy = ys - y
+
+    div = numpy.abs(numpy.gcd(dx, dy))
+
+    mask = div != 0
+
+    dx[mask] //= div[mask]
+    dy[mask] //= div[mask]
+
+    unique = set(zip(dx, dy))
+
+    return len(unique) - 1  # need to ignore the point itself
+
+
+def part1(data: TextIO) -> int:
+    xs, ys = read_asteroids(data)
+
+    return max(asteroids_visible(x, y, xs, ys) for x, y in zip(xs, ys))
+
+
+def part2(data: TextIO) -> int:
+    xs, ys = read_asteroids(data)
+
+    cx, cy = max(zip(xs, ys), key=lambda c: asteroids_visible(c[0], c[1], xs, ys))
+
+    dx = xs - cx
+    dy = ys - cy
+
+    angles = numpy.arctan2(dy, dx)
+    distances = numpy.abs(numpy.copy(dx)) + numpy.abs(numpy.copy(dy))
+
+    to_shoot = defaultdict(list)
+
+    for angle, distance, dx, dy in zip(angles, distances, dx, dy):
+        if distance == 0:
+            # The point itself
+            continue
+
+        to_shoot[angle].append((distance, dx, dy))
+
+    for distances in to_shoot.values():
+        distances.sort(reverse=True)
+
+    unique_angles = sorted(set(angles), reverse=True)
+
+    shot = 0
+
+    # First shoot from up clockwise
+    for angle in unique_angles:
+        if angle > math.pi / 2:
+            continue
+
+        shot += 1
+
+        _, dx, dy = to_shoot[angle].pop()
+
+    # Repeatedly shoot until you reach #200
+    while True:
+        for angle in unique_angles:
+            if not to_shoot[angle]:
+                # Nothing left to shoot
+                continue
+
+            shot += 1
+
+            _, dx, dy = to_shoot[angle].pop()
+
+            if shot == 200:
+                x = cx + dx
+                y = -(cy + dy)
+                return 100 * x + y
+