Part 1 2018 Day 25

2018/day25.py

@@ -0,0 +1,24 @@
+with open('day25-input', 'r') as file:
+  data = [l.strip('\n') for l in file]
+import numpy as np
+import re
+
+numbers = [[int(s) for s in re.findall(r'-?\d+', d)] for d in data]
+arr = np.array(numbers, dtype=np.int64)
+max_constellation_radius = 3
+constellation_ids = np.arange((len(arr)), dtype=np.int64)
+
+
+def points_in_range_of(index):
+  distances = np.abs(arr - arr[index]).sum(axis=1)
+  return np.argwhere(distances <= max_constellation_radius)[:,0]  # Note this will include the point itself
+
+
+for i in range(len(arr)):
+  points = points_in_range_of(i)
+  constellations_to_merge = constellation_ids[points]
+  constellation_id = constellation_ids[points].min()
+  for c in constellations_to_merge:
+    constellation_ids[constellation_ids == c] = constellation_id
+
+print(len(np.unique(constellation_ids)))  # Part 1