solved day 11

Author: shahata

src/2025/day11.js

@@ -0,0 +1,35 @@
+function memoize(fn) {
+  let memo = {};
+  return (...x) => {
+    let s = JSON.stringify(x);
+    return (memo[s] = memo[s] ?? fn(...x));
+  };
+}
+
+let solve = memoize((devices, curr, dac = true, fft = true) => {
+  if (curr === "out") return dac && fft ? 1 : 0;
+  if (curr === "dac") dac = true;
+  if (curr === "fft") fft = true;
+  return devices[curr].reduce(
+    (sum, next) => sum + solve(devices, next, dac, fft),
+    0,
+  );
+});
+
+function parse(input) {
+  let devices = {};
+  input.split("\n").forEach(line => {
+    let [name, rest] = line.split(": ");
+    let outputs = rest.split(" ");
+    devices[name] = outputs;
+  });
+  return devices;
+}
+
+export function part1(input) {
+  return solve(parse(input), "you");
+}
+
+export function part2(input) {
+  return solve(parse(input), "svr", false, false);
+}

src/2025/day11.test.js

@@ -0,0 +1,60 @@
+import { part1, part2 } from "./day11.js";
+import { describe, test, expect } from "vitest";
+import readInput from "../utils/read-input.js";
+
+let input = readInput(import.meta.url);
+
+describe("day11 2025", () => {
+  describe("part1", () => {
+    test("it should work for part 1 examples", () => {
+      expect(
+        part1(
+          [
+            "aaa: you hhh",
+            "you: bbb ccc",
+            "bbb: ddd eee",
+            "ccc: ddd eee fff",
+            "ddd: ggg",
+            "eee: out",
+            "fff: out",
+            "ggg: out",
+            "hhh: ccc fff iii",
+            "iii: out",
+          ].join("\n"),
+        ),
+      ).toEqual(5);
+    });
+
+    test("it should work for part 1 input", () => {
+      expect(part1(input)).toEqual(506);
+    });
+  });
+
+  describe("part2", () => {
+    test("it should work for part 2 examples", () => {
+      expect(
+        part2(
+          [
+            "svr: aaa bbb",
+            "aaa: fft",
+            "fft: ccc",
+            "bbb: tty",
+            "tty: ccc",
+            "ccc: ddd eee",
+            "ddd: hub",
+            "hub: fff",
+            "eee: dac",
+            "dac: fff",
+            "fff: ggg hhh",
+            "ggg: out",
+            "hhh: out",
+          ].join("\n"),
+        ),
+      ).toEqual(2);
+    });
+
+    test("it should work for part 2 input", () => {
+      expect(part2(input)).toEqual(385912350172800);
+    });
+  });
+});