Solve 2023-25 (terribly)

2023/25/index.ts

@@ -0,0 +1,85 @@
+import { multBy } from '../../utils/array.ts';
+import { randomInt } from '../../utils/random.ts';
+
+function trySolve(
+  nodes: { node: string; weight: number }[],
+  edges: [string, string][]
+) {
+  while (nodes.length > 2) {
+    const randEdgeIdx = randomInt(0, edges.length);
+    const [u, v] = edges.splice(randEdgeIdx, 1)[0];
+
+    const vertexU = nodes.find((n) => n.node === u)!;
+    const vertexVIdx = nodes.findIndex((n) => n.node === v);
+    const vertexV = nodes.splice(vertexVIdx, 1)[0];
+
+    const oldNodes = [u, v];
+    const mergedName = `(${u}:${v})`;
+
+    const newEdges = edges
+      .map(
+        (e) =>
+          [
+            oldNodes.includes(e[0]) ? mergedName : e[0],
+            oldNodes.includes(e[1]) ? mergedName : e[1]
+          ] as [string, string]
+      )
+      .filter((e) => e[0] !== e[1]);
+    edges.length = 0;
+    edges.push(...newEdges);
+
+    vertexU.node = mergedName;
+    vertexU.weight += vertexV.weight;
+  }
+  const edgeLength = edges.length;
+
+  const mult = multBy(nodes, (n) => n.weight);
+
+  return { edgeLength, mult };
+}
+
+export function solveFirst(input: string): number {
+  const regex = /^(\w*): (.*)$/gm;
+  const match = input.matchAll(regex);
+
+  const { edges, nodesSet } = Array.from(
+    match,
+    (m) => [m[1], m[2].split(' ')] as [string, string[]]
+  ).reduce(
+    ({ edges, nodesSet }, line) => {
+      nodesSet.add(line[0]);
+      line[1].forEach((n) => {
+        nodesSet.add(n);
+        edges.push([line[0], n]);
+      });
+
+      return { edges, nodesSet };
+    },
+    {
+      edges: [] as [string, string][],
+      nodesSet: new Set<string>()
+    }
+  );
+
+  let edgeLength, mult;
+  let i = 0;
+  do {
+    i++;
+    const result = trySolve(
+      Array.from(nodesSet, (n) => ({ node: n, weight: 1 })),
+      [...edges]
+    );
+    edgeLength = result.edgeLength;
+    mult = result.mult;
+  } while (edgeLength > 3);
+
+  console.log(`That took ${i} tries`);
+  console.log(mult);
+  return mult;
+}
+
+export function solveSecond(input: string): number {
+  // TODO: add code
+
+  return 0;
+}