refactor

Author: shahata

src/2025/day08.js

@@ -1,82 +1,63 @@
-function straightLineDistance3D(a, b) {
-  return Math.sqrt((a.x - b.x) ** 2 + (a.y - b.y) ** 2 + (a.z - b.z) ** 2);
-}
-
 function top3Circuits(junctions) {
   let circuitCounts = new Map();
-  for (let junction of junctions) {
-    if (junction.circuit === null) continue;
-    circuitCounts.set(
-      junction.circuit,
-      (circuitCounts.get(junction.circuit) || 0) + 1,
-    );
+  for (let { circuit } of junctions) {
+    if (circuit === null) continue;
+    circuitCounts.set(circuit, (circuitCounts.get(circuit) || 0) + 1);
   }
-  let counts = Array.from(circuitCounts.values());
-  counts.sort((a, b) => b - a);
+  let counts = Array.from(circuitCounts.values()).sort((a, b) => b - a);
   return counts.slice(0, 3).reduce((a, b) => a * b, 1);
 }
 
-function getAllPairs(junctions) {
-  let pairs = [];
-  for (let i = 0; i < junctions.length; i++) {
-    for (let j = i + 1; j < junctions.length; j++) {
-      let a = junctions[i];
-      let b = junctions[j];
-      let dist = straightLineDistance3D(a, b);
-      pairs.push({ a, b, dist });
-    }
-  }
-  return pairs.sort((p1, p2) => p1.dist - p2.dist);
-}
-
 function connectPair(pair, junctions) {
   let { a, b } = pair;
   if (a.circuit === null && b.circuit === null) {
     a.circuit = b.circuit = Symbol();
-  } else if (a.circuit !== null && b.circuit === null) {
-    b.circuit = a.circuit;
-  } else if (a.circuit === null && b.circuit !== null) {
-    a.circuit = b.circuit;
+  } else if (a.circuit === null || b.circuit === null) {
+    a.circuit = b.circuit = a.circuit || b.circuit;
   } else if (a.circuit !== b.circuit) {
-    let oldCircuit = b.circuit;
-    let newCircuit = a.circuit;
-    for (let j = 0; j < junctions.length; j++) {
-      if (junctions[j].circuit === oldCircuit) {
-        junctions[j].circuit = newCircuit;
-      }
-    }
+    junctions
+      .filter(junction => junction.circuit === b.circuit)
+      .forEach(junction => (junction.circuit = a.circuit));
   }
   return pair;
 }
 
 function allConnected(junctions) {
   let firstCircuit = junctions[0].circuit;
-  if (firstCircuit === null) return false;
-  for (let junction of junctions) {
-    if (junction.circuit !== firstCircuit) {
-      return false;
-    }
-  }
-  return true;
+  return (
+    firstCircuit !== null &&
+    junctions.every(junction => junction.circuit === firstCircuit)
+  );
 }
 
-export function part1(input, times = 1000) {
+function parse(input) {
   let junctions = input.split("\n").map(line => {
     let [x, y, z] = line.split(",").map(Number);
     return { x, y, z, circuit: null };
   });
-  let pairs = getAllPairs(junctions).slice(0, times);
-  for (let i = 0; i < pairs.length; i++) connectPair(pairs[i], junctions);
+  let pairs = [];
+  for (let i = 0; i < junctions.length; i++) {
+    for (let j = i + 1; j < junctions.length; j++) {
+      let a = junctions[i];
+      let b = junctions[j];
+      let dist = Math.sqrt(
+        (a.x - b.x) ** 2 + (a.y - b.y) ** 2 + (a.z - b.z) ** 2,
+      );
+      pairs.push({ a, b, dist });
+    }
+  }
+  return { junctions, pairs: pairs.sort((p1, p2) => p1.dist - p2.dist) };
+}
+
+export function part1(input, times = 1000) {
+  let { junctions, pairs } = parse(input);
+  for (let i = 0; i < times; i++) connectPair(pairs[i], junctions);
   return top3Circuits(junctions);
 }
 
 export function part2(input) {
-  let junctions = input.split("\n").map(line => {
-    let [x, y, z] = line.split(",").map(Number);
-    return { x, y, z, circuit: null };
-  });
   let pair;
-  let pairs = getAllPairs(junctions);
+  let { junctions, pairs } = parse(input);
   while (!allConnected(junctions)) pair = connectPair(pairs.shift(), junctions);
   return pair.a.x * pair.b.x;
 }