Update Advent of Code

Author: jargnar

.gitignore

@@ -1,3 +1,4 @@
+temp.py
 *.txt
 *.csv
 .ipynb_checkpoints/

advent_of_code_2021.ipynb

@@ -11,11 +11,10 @@
   {
    "cell_type": "code",
    "execution_count": 1,
-   "id": "a3a0e999",
+   "id": "e8c9d0ce",
    "metadata": {},
    "outputs": [],
    "source": [
-    "// Setup\n",
     "import java.io.File"
    ]
   },
@@ -36,6 +35,7 @@
    ],
    "source": [
     "// Day 1\n",
+    "\n",
     "val readings = File(\"1.txt\").readLines().map { it.toInt() }\n",
     "val part1 = readings.windowed(2).count { (a, b) -> a < b }\n",
     "val part2 = readings.windowed(3).windowed(2).count { (a, b) -> a.sum() < b.sum() }\n",
@@ -61,6 +61,7 @@
    ],
    "source": [
     "// Day 2\n",
+    "\n",
     "val moves = File(\"2.txt\").readLines().map { it.split(\" \") }\n",
     "var horizontal = 0\n",
     "var depth = 0\n",
@@ -157,7 +158,7 @@
     }
    ],
    "source": [
-    "// day 6\n",
+    "// Day 6\n",
     "\n",
     "var fishes = File(\"6.txt\")\n",
     "    .readLines()[0]\n",
@@ -185,33 +186,120 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "id": "088da5fa",
+   "execution_count": 6,
+   "id": "410107ca",
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "355592\n"
+      "355592\n",
+      "101618069\n"
      ]
     }
    ],
    "source": [
-    "// day 7\n",
+    "// Day 7\n",
+    "\n",
+    "var positions = File(\"7.txt\")\n",
+    "    .readLines()[0]\n",
+    "    .split(\",\")\n",
+    "    .map { it.toInt() }\n",
     "\n",
-    "var positions = File(\"7.txt\").readLines()[0].split(\",\").map { it.toInt() }\n",
-    "val median = positions.sorted().let { (it[it.size / 2] + it[(it.size - 1) / 2]) / 2 }\n",
-    "val mean = ceil(positions.average())\n",
+    "val median = positions\n",
+    "    .sorted()\n",
+    "    .let { (it[it.size / 2] + it[(it.size - 1) / 2]) / 2 }\n",
+    "\n",
+    "fun gauss(n: Int) = n * (n + 1) / 2\n",
     "\n",
     "println(positions.sumOf { abs(it - median) })\n",
-    "println((1..positions.maxOrNull()!!).minOf { p -> positions.sumOf {  (1..abs(p - it)).sum() } })"
+    "println((1..positions.maxOrNull()!!).minOf { p -> positions.sumOf {  gauss(abs(p - it)) } })"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "ef0c50e7",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "554"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "// Day 8 part 1\n",
+    "\n",
+    "val signals = File(\"8.txt\").readLines()\n",
+    "\n",
+    "signals\n",
+    "    .map { it.split(\" | \").last().split(\" \") }\n",
+    "    .flatten()\n",
+    "    .groupingBy { it.length }\n",
+    "    .eachCount()\n",
+    "    .filterKeys { it in listOf(2, 3, 4, 7) }\n",
+    "    .values\n",
+    "    .sum()\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "b04f6fa7",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "537\n"
+     ]
+    }
+   ],
+   "source": [
+    "// Day 9 part 1\n",
+    "\n",
+    "val heights = File(\"9.txt\").readLines().map { it.toList().map { Character.getNumericValue(it) } }\n",
+    "\n",
+    "val row_size = heights.size\n",
+    "val col_size = heights[0].size\n",
+    "var low_pnts = mutableListOf<Int>()\n",
+    "\n",
+    "fun List<List<Int>>.at(i: Int, j: Int): Int {\n",
+    "    val inf = 99999999\n",
+    "    if (this.getOrNull(i).isNullOrEmpty()) return inf\n",
+    "    else if (this[i].getOrNull(j) == null) return inf\n",
+    "    else return this[i][j]\n",
+    "}\n",
+    "\n",
+    "for (i in 0 until row_size) {\n",
+    "    for (j in 0 until col_size) {\n",
+    "        val neighbours = listOf(\n",
+    "            heights.at(i - 1, j - 1), heights.at(i - 1, j), heights.at(i - 1, j + 1), \n",
+    "            heights.at(i, j - 1), heights.at(i, j + 1),\n",
+    "            heights.at(i + 1, j - 1), heights.at(i + 1, j), heights.at(i + 1, j + 1)\n",
+    "        )\n",
+    "        if (neighbours.all { it > heights[i][j] }) {\n",
+    "            low_pnts += heights[i][j] + 1\n",
+    "        }\n",
+    "    }\n",
+    "}\n",
+    "\n",
+    "println(low_pnts.sum())"
    ]
   },
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "d68cd1fd",
+   "id": "1b43b63a",
    "metadata": {},
    "outputs": [],
    "source": []