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 = np.logical_and(field[:-1,:,:] == 1, field[1:,:,:] == -1).sum() surface_area += np.logical_and(field[1:,:,:] == 1, field[:-1,:,:] == -1).sum() surface_area += np.logical_and(field[:,:-1,:] == 1, field[:,1:,:] == -1).sum() surface_area += np.logical_and(field[:,1:,:] == 1, field[:,:-1,:] == -1).sum() surface_area += np.logical_and(field[:,:,:-1] == 1, field[:,:,1:] == -1).sum() surface_area += np.logical_and(field[:,:,1:] == 1, field[:,:,:-1] == -1).sum() return surface_area print(f'Part 2 (sample): {count_faces_2(sample_coords)}') print(f'Part 2: {count_faces_2(coords)}')