2022: Add day 18.

HoffmannChristian · HoffmannChristian · commit 2cb1c82a8447 · 2022-12-27T11:21:50.000+01:00
diff --git a/2022/advent_of_code_2022.ipynb b/2022/advent_of_code_2022.ipynb
@@ -1481,6 +1481,86 @@
    "source": [
     "#TODO"
    ]
+  },
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Day 18: Boiling Boulders\n",
+    "\n",
+    "What is the surface area of your scanned lava droplet?"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def are_connected(cube0, cube1):\n",
+    "    return abs(cube0[0] - cube1[0]) == 1 and cube0[1] == cube1[1] and cube0[2] == cube1[2] \\\n",
+    "        or cube0[0] == cube1[0] and abs(cube0[1] - cube1[1]) == 1 and cube0[2] == cube1[2] \\\n",
+    "        or cube0[0] == cube1[0] and cube0[1] == cube1[1] and abs(cube0[2] - cube1[2]) == 1\n",
+    "\n",
+    "def get_num_connected_sides(cube, cubes):\n",
+    "    return sum(1 for c in cubes if are_connected(cube, c))\n",
+    "\n",
+    "def get_surface_area_of_cube(cube, cubes):\n",
+    "    return 6 - get_num_connected_sides(cube, cubes)\n",
+    "\n",
+    "lines = open('18_input.txt', 'r').readlines()\n",
+    "lines = [line.strip() for line in lines]\n",
+    "\n",
+    "cubes = [tuple([int(coord) for coord in line.split(',')]) for line in lines]\n",
+    "sum(get_surface_area_of_cube(c, cubes) for c in cubes)"
+   ]
+  },
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "What is the exterior surface area of your scanned lava droplet?"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def change_tuple_at_index(t, index, modifier):\n",
+    "    l = list(t)\n",
+    "    l[index] += modifier\n",
+    "    return tuple(l)\n",
+    "\n",
+    "def process_candidate(cube, index, modifier, cubes, visited_air, air_to_visit, area):\n",
+    "    candidate = change_tuple_at_index(cube, index, modifier)\n",
+    "    if candidate in cubes:\n",
+    "        area += 1\n",
+    "    elif candidate not in visited_air:\n",
+    "        air_to_visit.add(candidate)\n",
+    "    return air_to_visit, area\n",
+    "\n",
+    "def process_cube(cube, cubes, max_coords, visited_air, air_to_visit, area):\n",
+    "    for i in range(len(cube)):\n",
+    "        if cube[i] >= 0:\n",
+    "            air_to_visit, area = process_candidate(cube, i, -1, cubes, visited_air, air_to_visit, area)\n",
+    "        if cube[i] < max_coords[i]:\n",
+    "            air_to_visit, area = process_candidate(cube, i, 1, cubes, visited_air, air_to_visit, area)\n",
+    "    return air_to_visit, area\n",
+    "\n",
+    "max_coords =  tuple([max(i)+1 for i in zip(*cubes)])\n",
+    "air_to_visit, visited_air = set([max_coords]), set()\n",
+    "\n",
+    "area = 0\n",
+    "while air_to_visit:\n",
+    "    cube = air_to_visit.pop()\n",
+    "    visited_air.add(cube)\n",
+    "    air_to_visit, area = process_cube(cube, cubes, max_coords, visited_air, air_to_visit, area)\n",
+    "area"
+   ]
   }
  ],
  "metadata": {
