solved day10b

days/test_day10.py

@@ -1,4 +1,4 @@
-from math import atan2
+from math import atan2, sqrt
 import os
 from typing import Tuple
 
@@ -6,20 +6,45 @@ from typing import Tuple
 inputfile = os.path.join(os.path.dirname(__file__), "input/day10_input")
 
 
+def get_asteroids():
+    with open(inputfile) as fp:
+        lines = [x.rstrip() for x in fp.readlines()]
+        return [(x, y)
+                for y, line in enumerate(lines)
+                for x, m in enumerate(line)
+                if m == '#']
+
+
 def calc_arc(origin: Tuple[int, int], target: Tuple[int, int]) -> float:
     return atan2(target[0] - origin[0], target[1] - origin[1])
 
 
 def test_day10a():
-    with open(inputfile) as fp:
-        lines = [x.rstrip() for x in fp.readlines()]
-    asts = [(x, y)
-            for x, line in enumerate(lines)
-            for y, m in enumerate(line)
-            if m == '#']
-
     max = 0
+    found = (0, 0)
+    asts = get_asteroids()
     for my in asts:
         angles = {calc_arc(my, target) for target in asts}
-        max = len(angles) if len(angles) > max else max
+        if len(angles) > max:
+            max = len(angles)
+            found = my
+
+    print(f'Station is at {found} with {max} visible asteroids')
     assert max == 303
+
+
+def test_day10b():
+    station = (26, 29)
+    res = None
+    count = 0
+    asts = get_asteroids()
+    asts.remove(station)
+    while not res:
+        angles = {calc_arc(station, target): target for target in asts}
+        for ang in sorted(angles.keys(), reverse=True):
+            asts.remove(angles[ang])
+            count += 1
+            if count == 200:
+                res = angles[ang]
+                break
+    assert res[0] * 100 + res[1] == 408