Year 2024, Day 15, Part 1

Author: Schlauer-Hax

clients/typescript/solutions/S2415.ts

@@ -0,0 +1,112 @@
+import ISolution from "./ISolution.ts";
+
+export default class S2415 implements ISolution {
+  firstPart(input: string): (number | string) | Promise<number | string> {
+    const [ rawmap, rawinstructions ] = input.split("\n\n");
+    const map = rawmap.split("\n").map((row) => row.split(""));
+    const instructions = rawinstructions.split("");
+    for (const instruction of instructions) {
+      const y = map.findIndex((row) => row.includes("@"));
+      const x = map[ y ].indexOf("@");
+      const move = this.moveable(map, x, y, instruction);
+      if (move > 0) {
+        if (instruction === "<") {
+
+          map[ y ][ x ] = ".";
+          map[ y ][ x - 1 ] = "@";
+          if (move > 1) {
+            map[ y ][ x - move ] = "O";
+          }
+        }
+        if (instruction === ">") {
+          map[ y ][ x ] = ".";
+          map[ y ][ x + 1 ] = "@";
+          if (move > 1) {
+            map[ y ][ x + move ] = "O";
+          }
+        }
+        if (instruction === "^") {
+          map[ y ][ x ] = ".";
+          map[ y - 1 ][ x ] = "@";
+          if (move > 1) {
+            map[ y - move ][ x ] = "O";
+          }
+        }
+        if (instruction === "v") {
+          map[ y ][ x ] = ".";
+          map[ y + 1 ][ x ] = "@";
+          if (move > 1) {
+            map[ y + move ][ x ] = "O";
+          }
+        }
+      }
+    }
+    // console.log(map.map((row) => row.join("")).join("\n"));
+    return map.map((row, y) => row.map((cell, x) => cell === "O" ? 100*y+x : 0)).flat().reduce((a, b) => a + b);
+  }
+  moveable(map: string[][], x: number, y: number, direction: string): number {
+    if (direction === "<") {
+      if (map[ y ][ x - 1 ] === "#") {
+        return 0;
+      }
+      if (map[ y ][ x - 1 ] === "O") {
+        const moves = this.moveable(map, x - 1, y, direction);
+        return moves > 0 ? moves + 1 : 0;
+      }
+      if (map[y][x-1] === "]") {
+        const moves = this.moveable(map, x - 2, y, direction);
+        return moves > 0 ? moves + 2 : 0;
+      }
+      return 1;
+    }
+    if (direction === ">") {
+      if (map[ y ][ x + 1 ] === "#") {
+        return 0;
+      }
+      if (map[ y ][ x + 1 ] === "O") {
+        const moves = this.moveable(map, x + 1, y, direction);
+        return moves > 0 ? moves + 1 : 0;
+      }
+      if (map[y][x+1] === "[") {
+        const moves = this.moveable(map, x + 2, y, direction);
+        return moves > 0 ? moves + 2 : 0;
+      }
+      return 1;
+    }
+    if (direction === "^") {
+      if (map[ y - 1 ][ x ] === "#") {
+        return 0;
+      }
+      if (map[ y - 1 ][ x ] === "O") {
+        const moves = this.moveable(map, x, y - 1, direction);
+        return moves > 0 ? moves + 1 : 0;
+      }
+      if (map[y-1][x] === "[") {
+        const moves1 = this.moveable(map, x, y - 1, direction);
+        const moves2 = this.moveable(map, x+1, y - 1, direction);
+        return Math.min(moves1, moves2) > 0 ? Math.max(moves1, moves2) + 1 : 0;
+      }
+      if (map[y-1][x] === "]") {
+        const moves1 = this.moveable(map, x, y - 1, direction);
+        const moves2 = this.moveable(map, x-1, y - 1, direction);
+        return Math.min(moves1, moves2) > 0 ? Math.max(moves1, moves2) + 1 : 0;
+      }
+      return 1;
+    }
+    if (direction === "v") {
+      if (map[ y + 1 ][ x ] === "#") {
+        return 0;
+      }
+      if (map[ y + 1 ][ x ] === "O") {
+        const moves = this.moveable(map, x, y + 1, direction);
+        return moves > 0 ? moves + 1 : 0;
+      }
+      return 1;
+    }
+    return 0;
+  }
+  secondPart(input: string): (number | string) | Promise<number | string> {
+    return "";
+  }
+
+}