feat: 2024 Day 24 Part 1

Author: mfulton26

2024/day/24/monitoringDevices.ts

@@ -0,0 +1,56 @@
+export type WireValues = ReturnType<typeof parseInitialWireValues>;
+export type GateConnections = ReturnType<typeof parseGateConnections>;
+
+const gateRegExp = /^(?<a>\S+) (?<op>AND|OR|XOR) (?<b>\S+) -> (?<c>\S+)$/gm;
+
+const ops: Record<string, (x: number, y: number) => number> = {
+  AND: (a, b) => a & b,
+  OR: (a, b) => a | b,
+  XOR: (a, b) => a ^ b,
+};
+
+function parseInitialWireValues(text: string) {
+  return text.split("\n").reduce((map, line) => {
+    const [wire, value] = line.split(": ");
+    return map.set(wire, +value);
+  }, new Map<string, number>());
+}
+
+function parseGateConnections(text: string) {
+  return text.matchAll(gateRegExp).reduce(
+    (map, [, a, op, b, c]) => map.set({ a, op, b }, c),
+    new Map<{ a: string; op: string; b: string }, string>(),
+  );
+}
+
+export function parseInput(input: string) {
+  const [top, bottom] = input.split("\n\n");
+  const initialWireValues = parseInitialWireValues(top);
+  const gateConnections = parseGateConnections(bottom);
+  return { initialWireValues, gateConnections };
+}
+
+export function output(
+  initialWireValues: WireValues,
+  gateConnections: GateConnections,
+) {
+  const wireValues = new Map(initialWireValues);
+  const pendingGateConnections = new Map(gateConnections);
+  while (pendingGateConnections.size) {
+    for (const [gate, wire] of pendingGateConnections) {
+      const { a, op, b } = gate;
+      const x = wireValues.get(a), y = wireValues.get(b);
+      if (x === undefined || y === undefined) continue;
+      const z = ops[op](x, y);
+      wireValues.set(wire, z);
+      pendingGateConnections.delete(gate);
+    }
+  }
+  let result = 0n;
+  for (const [wire, value] of wireValues) {
+    if (value === 0 || !wire.startsWith("z")) continue;
+    const bit = BigInt(wire.slice(1));
+    result ^= 2n ** bit;
+  }
+  return Number(result);
+}

2024/day/24/part/1/solve.test.ts

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+import solve from "./solve.ts";
+
+import { assertEquals } from "@std/assert";
+
+Deno.test("example", () => {
+  const input = `\
+x00: 1
+x01: 1
+x02: 1
+y00: 0
+y01: 1
+y02: 0
+
+x00 AND y00 -> z00
+x01 XOR y01 -> z01
+x02 OR y02 -> z02`;
+
+  assertEquals(solve(input), 4);
+});
+
+Deno.test("larger example", () => {
+  const input = `\
+x00: 1
+x01: 0
+x02: 1
+x03: 1
+x04: 0
+y00: 1
+y01: 1
+y02: 1
+y03: 1
+y04: 1
+
+ntg XOR fgs -> mjb
+y02 OR x01 -> tnw
+kwq OR kpj -> z05
+x00 OR x03 -> fst
+tgd XOR rvg -> z01
+vdt OR tnw -> bfw
+bfw AND frj -> z10
+ffh OR nrd -> bqk
+y00 AND y03 -> djm
+y03 OR y00 -> psh
+bqk OR frj -> z08
+tnw OR fst -> frj
+gnj AND tgd -> z11
+bfw XOR mjb -> z00
+x03 OR x00 -> vdt
+gnj AND wpb -> z02
+x04 AND y00 -> kjc
+djm OR pbm -> qhw
+nrd AND vdt -> hwm
+kjc AND fst -> rvg
+y04 OR y02 -> fgs
+y01 AND x02 -> pbm
+ntg OR kjc -> kwq
+psh XOR fgs -> tgd
+qhw XOR tgd -> z09
+pbm OR djm -> kpj
+x03 XOR y03 -> ffh
+x00 XOR y04 -> ntg
+bfw OR bqk -> z06
+nrd XOR fgs -> wpb
+frj XOR qhw -> z04
+bqk OR frj -> z07
+y03 OR x01 -> nrd
+hwm AND bqk -> z03
+tgd XOR rvg -> z12
+tnw OR pbm -> gnj`;
+
+  assertEquals(solve(input), 2024);
+});

2024/day/24/part/1/solve.ts

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+import { output, parseInput } from "../../monitoringDevices.ts";
+
+export default function solve(input: string) {
+  const { initialWireValues, gateConnections } = parseInput(input);
+  return output(initialWireValues, gateConnections);
+}