2022 Day 18 Python import solution

2022/day18.py

@@ -0,0 +1,67 @@
+from helpers import *
+from skimage.morphology import flood
+coords = [tuple(line_to_numbers(line)) for line in read_day(18).split('\n')]
+
+sample_coords = [tuple(line_to_numbers(line)) for line in '''
+2,2,2
+1,2,2
+3,2,2
+2,1,2
+2,3,2
+2,2,1
+2,2,3
+2,2,4
+2,2,6
+1,2,5
+3,2,5
+2,1,5
+2,3,5
+'''.strip().split('\n')]
+
+def count_faces(coords: list[tuple[int,int,int]]):
+	# print(coords)
+	surface_area = 0
+	for (x,y,z) in coords:
+		if (x+1,y,z) not in coords:
+			surface_area += 1
+		if (x-1,y,z) not in coords:
+			surface_area += 1
+		if (x,y+1,z) not in coords:
+			surface_area += 1
+		if (x,y-1,z) not in coords:
+			surface_area += 1
+		if (x,y,z+1) not in coords:
+			surface_area += 1
+		if (x,y,z-1) not in coords:
+			surface_area += 1
+	return surface_area
+
+print(f'Part 1 (sample): {count_faces(sample_coords)}')
+print(f'Part 1: {count_faces(coords)}')
+
+def count_faces_2(coords: list[tuple[int,int,int]]):
+	# we pad to ensure the outer edges are fine
+	field = np.zeros((25,25,25), dtype=np.int8)
+	for (x,y,z) in coords:
+		field[x+1,y+1,z+1] = 1
+	field[flood(field, (0,0,0), connectivity=1)] = -1
+
+	surface_area = 0
+	for (x,y,z) in np.argwhere(field == 1):
+		if field[x+1,y,z] == -1:
+			surface_area += 1
+		if field[x-1,y,z] == -1:
+			surface_area += 1
+		if field[x,y+1,z] == -1:
+			surface_area += 1
+		if field[x,y-1,z] == -1:
+			surface_area += 1
+		if field[x,y,z+1] == -1:
+			surface_area += 1
+		if field[x,y,z-1] == -1:
+			surface_area += 1
+	return surface_area
+
+
+print(f'Part 2 (sample): {count_faces_2(sample_coords)}')
+print(f'Part 2: {count_faces_2(coords)}')