Added 2017 day 13

Author: plasmapper

2017/13/code.mjs

@@ -0,0 +1,139 @@
+import { delay, Console, PixelMap, leastCommonMultiple } from "../../utility.mjs";
+
+const packetColorIndex = 1;
+const packetColor = "#ffffff";
+const scannerColorIndex = 2;
+const scannerColor = "#999999";
+const caughtColorIndex = 3;
+const caughtColor = "#ff0000";
+
+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 {number[]} Scanner ranges.
+   */
+  parse(input) {
+    let consoleLine = this.solConsole.addLine("Parsing...");
+
+    let scannerRanges = [];
+    input.trim().split(/\r?\n/).forEach((line, index) => {
+      let match = line.match(/^(\d+): (\d+)$/);
+      if (match == null)
+        throw new Error(`Invalid data in line ${index + 1}`);
+      let layerIndex = parseInt(match[1]);
+      let range = parseInt(match[2]);
+      for (let i = scannerRanges.length; i <= layerIndex; i++)
+        scannerRanges.push(0);
+      scannerRanges[layerIndex] = range;
+    });
+
+    consoleLine.innerHTML += " done.";
+    return scannerRanges;
+  }
+
+
+  /**
+   * Finds the severity of trip through the firewall.
+   * @param {number} part Puzzle part.
+   * @param {string} input Puzzle input.
+   * @param {boolean} visualization Enable visualization.
+   * @returns {number} Severity of trip through the firewall.
+   */
+  async solve(part, input, visualization) {
+    try {
+      this.isSolving = true;
+
+      let scannerRanges = this.parse(input);
+
+      let solConsoleLine;
+      let pixelMap = new PixelMap(scannerRanges.length, Math.max(...scannerRanges, 1));
+      if (visualization) {
+        solConsoleLine = this.solConsole.addLine();
+
+        this.visContainer.append(pixelMap.container);
+        pixelMap.palette[packetColorIndex] = packetColor;
+        pixelMap.palette[scannerColorIndex] = scannerColor;
+        pixelMap.palette[caughtColorIndex] = caughtColor;
+      }
+
+      let maxPacketDelay = scannerRanges.reduce((acc, e) => leastCommonMultiple(acc, Math.max(1, (e - 1) * 2)), 1);
+
+      for (let packetDelay = 0; packetDelay < maxPacketDelay; packetDelay++) {
+        let caught = false;
+        let severity = 0;
+        for (let i = 0; i < scannerRanges.length; i++) {
+          if (scannerRanges[i] > 0 && (scannerRanges[i] == 1 || (packetDelay + i) % ((scannerRanges[i] - 1) * 2) == 0)) {
+            caught = true;
+            severity += i * scannerRanges[i];
+          }
+        }
+
+        if (part == 1 || (part == 2 && !caught)) {
+          if (visualization) {
+            if (part == 2)
+              solConsoleLine.innerHTML = `Delay: ${packetDelay}.`;
+
+            severity = 0;
+            for (let i = 0; i < scannerRanges.length; i++) {
+              if (this.isStopping)
+                  return;
+
+              for (let x = 0; x < pixelMap.width; x++) {
+                let scannerY = -1;
+                if (scannerRanges[x] == 1)
+                  scannerY = 0;
+                else if (scannerRanges[x] > 1) {
+                  scannerY = (packetDelay + i) % ((scannerRanges[x] - 1) * 2);
+                  if (scannerY >= scannerRanges[x])
+                    scannerY = (scannerRanges[x] - 2) - (scannerY - scannerRanges[x]);
+                }
+
+                for (let y = 0; y < pixelMap.height; y++) {
+                  pixelMap.drawPixel(x, y, scannerY == y ? scannerColorIndex : 0);
+                }
+              }
+
+              pixelMap.drawPixel(i, 0, pixelMap.image[0][i] == 0 ? packetColorIndex : caughtColorIndex);
+              if (pixelMap.image[0][i] == caughtColorIndex)
+                severity += i * scannerRanges[i];
+              if (part == 1)
+                solConsoleLine.innerHTML = `Severity: ${severity}.`;
+
+              await delay(100);
+            }
+          }
+
+          return part == 1 ? severity : packetDelay;
+        }          
+      }
+
+      throw new Error("Solution not found");
+    }
+    
+    finally {
+      this.isSolving = false;
+    }
+  }
+
+  /**
+   * Stops solving the puzzle.
+   */
+  async stopSolving() {
+    this.isStopping = true;
+    while (this.isSolving)
+      await(delay(10));
+    this.isStopping = false;
+  }
+}

2017/13/testInput.txt

@@ -0,0 +1,4 @@
+0: 3
+1: 2
+4: 4
+6: 4

tree.mjs

@@ -446,6 +446,10 @@ export const years = [
       {
         name: "Day 12: Digital Plumber", path: "./2017/12", taskUrl: "https://adventofcode.com/2017/day/12",
         answers: {part1: 6, part2: 2}
+      },
+      {
+        name: "Day 13: Packet Scanners", path: "./2017/13", taskUrl: "https://adventofcode.com/2017/day/13",
+        answers: {part1: 24, part2: 10}
       }
     ]
   },