solved day 23

Author: shahata

src/2024/day23.js

@@ -0,0 +1,37 @@
+function addOneToNetwork(network, connections = network) {
+  let set = new Set();
+  network.forEach(connection => {
+    let as = connection
+      .map(c => {
+        return connections
+          .filter(other => other.includes(c))
+          .map(a => a.find(x => x !== c));
+      })
+      .map(a => new Set(a));
+    let result = as.reduce((a, b) => a.intersection(b));
+    result.forEach(x => set.add([...connection, x].sort().join(",")));
+  });
+  return set;
+}
+
+export function part1(input) {
+  let connections = input.split("\n").map(line => {
+    let [a, b] = line.split("-").sort();
+    return [a, b];
+  });
+  let set = addOneToNetwork(connections);
+  return [...set].filter(x => x.match(/(^t|,t)/)).length;
+}
+
+export function part2(input) {
+  let connections = input.split("\n").map(line => {
+    let [a, b] = line.split("-").sort();
+    return [a, b];
+  });
+  let network = connections;
+  while (network.length > 1) {
+    let next = addOneToNetwork(network, connections);
+    network = [...next].map(x => x.split(","));
+  }
+  return network[0].sort().join(",");
+}

src/2024/day23.spec.js

@@ -0,0 +1,100 @@
+import { part1, part2 } from "./day23.js";
+import readInput from "../utils/read-input.js";
+
+const input = readInput(import.meta.url);
+
+describe("day23 2024", () => {
+  describe("part1", () => {
+    test("it should work for part 1 examples", () => {
+      expect(
+        part1(
+          [
+            "kh-tc",
+            "qp-kh",
+            "de-cg",
+            "ka-co",
+            "yn-aq",
+            "qp-ub",
+            "cg-tb",
+            "vc-aq",
+            "tb-ka",
+            "wh-tc",
+            "yn-cg",
+            "kh-ub",
+            "ta-co",
+            "de-co",
+            "tc-td",
+            "tb-wq",
+            "wh-td",
+            "ta-ka",
+            "td-qp",
+            "aq-cg",
+            "wq-ub",
+            "ub-vc",
+            "de-ta",
+            "wq-aq",
+            "wq-vc",
+            "wh-yn",
+            "ka-de",
+            "kh-ta",
+            "co-tc",
+            "wh-qp",
+            "tb-vc",
+            "td-yn",
+          ].join("\n"),
+        ),
+      ).toEqual(7);
+    });
+
+    test("it should work for part 1 input", () => {
+      expect(part1(input)).toEqual(1175);
+    });
+  });
+
+  describe("part2", () => {
+    test("it should work for part 2 examples", () => {
+      expect(
+        part2(
+          [
+            "kh-tc",
+            "qp-kh",
+            "de-cg",
+            "ka-co",
+            "yn-aq",
+            "qp-ub",
+            "cg-tb",
+            "vc-aq",
+            "tb-ka",
+            "wh-tc",
+            "yn-cg",
+            "kh-ub",
+            "ta-co",
+            "de-co",
+            "tc-td",
+            "tb-wq",
+            "wh-td",
+            "ta-ka",
+            "td-qp",
+            "aq-cg",
+            "wq-ub",
+            "ub-vc",
+            "de-ta",
+            "wq-aq",
+            "wq-vc",
+            "wh-yn",
+            "ka-de",
+            "kh-ta",
+            "co-tc",
+            "wh-qp",
+            "tb-vc",
+            "td-yn",
+          ].join("\n"),
+        ),
+      ).toEqual("co,de,ka,ta");
+    });
+
+    test("it should work for part 2 input", () => {
+      expect(part2(input)).toEqual("bw,dr,du,ha,mm,ov,pj,qh,tz,uv,vq,wq,xw");
+    });
+  });
+});