Added 2017 day 19

Author: plasmapper

2017/14/code.mjs

@@ -30,7 +30,6 @@ export default class  {
     return keyString;
   }
 
-
   /**
    * Finds the number of used grid squares (part 1) or the number of regions (part 2).
    * @param {number} part Puzzle part.

2017/19/code.mjs

@@ -0,0 +1,137 @@
+import { delay, Console, Vector2D, PixelMap } from "../../utility.mjs";
+
+const pathColorIndex = 1;
+const pathColor = "#999999";
+const packetColorIndex = 2;
+const packetColor = "#ffffff";
+const letterColorIndex = 3;
+const letterColor = "#ffff00";
+
+export default class  {
+  /**
+   * @param {Console} solConsole Solution console.
+   * @param {HTMLElement} visContainer Visualization container.
+   */
+  constructor(solConsole, visContainer) {
+    this.isSolving = false;
+    this.isStopping = false;
+    this.solConsole = typeof solConsole !== "undefined" ? solConsole : new Console();
+    this.visContainer = visContainer;
+  }
+  
+  /**
+   * Parses the puzzle input.
+   * @param {string} input Puzzle input.
+   * @returns {{
+   * map: number[][],
+   * letters: object<string,Vector2D>,
+   * }} Map and letters.
+   */
+  parse(input) {
+    let consoleLine = this.solConsole.addLine("Parsing...");
+
+    let letters = {};
+    let map = input.split(/\r?\n/).filter(e => e != "").map((line, index, lines) => {
+      if (line.length != lines[0].length)
+        throw new Error(`Invalid length of line ${index + 1}`);
+      if (!/^[A-Z\-\|\+\s]+$/.test(line))
+        throw new Error(`Invalid data in line ${index + 1}`);
+      let symbols = line.split("");
+      for (let x = 0; x < symbols.length; x++) {
+        if (/[A-Z]/.test(symbols[x]))
+          letters[symbols[x]] = new Vector2D(x, index);
+      }
+      return symbols.map(e => e != " " ? pathColorIndex : 0);
+    });
+
+    if (map.length == 0)
+      throw new Error("Invalid input data");
+
+    if (map[0].every(e => e == 0))
+      throw new Error("Start not found"); 
+
+    consoleLine.innerHTML += " done.";
+    return { map, letters };
+  }
+
+  /**
+   * Finds the sequence of letters along the path (part 1) or the number of steps (part 2).
+   * @param {number} part Puzzle part.
+   * @param {string} input Puzzle input.
+   * @param {boolean} visualization Enable visualization.
+   * @returns {string|number} Sequence of letters along the path (part 1) or the number of steps (part 2).
+   */
+  async solve(part, input, visualization) {
+    try {
+      this.isSolving = true;
+
+      let {map, letters} = this.parse(input);
+
+      let mapWidth = map[0].length, mapHeight = map.length;
+
+      let solConsoleLine;
+      let pixelMap = new PixelMap(mapWidth, mapHeight);
+      if (visualization) {
+        solConsoleLine = this.solConsole.addLine(part == 1 ? "Letter sequence: ." : "Step: 1.");
+        this.visContainer.append(pixelMap.container);
+        pixelMap.palette[pathColorIndex] = pathColor;
+        pixelMap.palette[packetColorIndex] = packetColor;
+        pixelMap.palette[letterColorIndex] = letterColor;
+        pixelMap.draw(map);
+        for (let letter in letters)
+          pixelMap.drawPixel(letters[letter].x, letters[letter].y, letterColorIndex);
+      }
+
+      let letterSequence = "", step = 1;
+      let position = new Vector2D(map[0].indexOf(pathColorIndex), 0);
+      let letter = Object.keys(letters).find(e => letters[e].equals(position));
+      if (letter != undefined)
+        letterSequence += letter;
+      if (visualization)
+        pixelMap.drawPixel(position.x, position.y, packetColorIndex);
+
+      let direction = new Vector2D(0, 1);
+      let directions = [new Vector2D(1, 0), new Vector2D(0, 1), new Vector2D(-1, 0), new Vector2D(0, -1)];
+
+      while (1) {
+        if (this.isStopping)
+          return;
+
+        let nextPosition = [direction, ...directions.filter(e => !e.equals(direction) && !e.equals(direction.clone().multiply(-1)))]
+          .map(dir => position.clone().add(dir))
+          .filter(nextPosition => nextPosition.x >= 0 && nextPosition.x < mapWidth && nextPosition.y >= 0 && nextPosition.y < mapHeight && map[nextPosition.y][nextPosition.x] != 0)[0];
+
+        if (nextPosition == undefined)
+          return part == 1 ? letterSequence : step;
+
+        step++;
+        direction = nextPosition.clone().subtract(position);
+        position = nextPosition;
+
+        letter = Object.keys(letters).find(e => letters[e].equals(position));
+        if (letter != undefined)
+          letterSequence += letter;
+
+        if (visualization && pixelMap.image[position.y][position.x] == pathColorIndex) {
+          pixelMap.drawPixel(position.x, position.y, packetColorIndex);
+          solConsoleLine.innerHTML = part == 1 ? `Letter sequence: ${letterSequence}.` : `Step: ${step}.`;
+          await delay(1);
+        }
+      }
+    }
+    
+    finally {
+      this.isSolving = false;
+    }
+  }
+
+  /**
+   * Stops solving the puzzle.
+   */
+  async stopSolving() {
+    this.isStopping = true;
+    while (this.isSolving)
+      await(delay(10));
+    this.isStopping = false;
+  }
+}

2017/19/testInput.txt

@@ -0,0 +1,6 @@
+     |          
+     |  +--+    
+     A  |  C    
+ F---|----E|--+ 
+     |  |  |  D 
+     +B-+  +--+ 

tree.mjs

@@ -470,6 +470,10 @@ export const years = [
       {
         name: "Day 18: Duet", path: "./2017/18", taskUrl: "https://adventofcode.com/2017/day/18",
         answers: {part1: 4, part2: 1}
+      },
+      {
+        name: "Day 19: A Series of Tubes", path: "./2017/19", taskUrl: "https://adventofcode.com/2017/day/19",
+        answers: {part1: "ABCDEF", part2: 38}
       }
     ]
   },