AoC 2024 - Day 24 (solution, part I)

2024/ts/day-24/code.ts

@@ -0,0 +1,123 @@
+// Solution for day 24 of advent of code 2024
+
+import { readInputLines, readInput } from "../system/aoc-helper";
+import "../utils/array-helpers";
+import { Puzzle } from "../model/puzzle";
+
+type Wire = { name: string, value: "true" | "false" | "unknown" };
+
+type Gate = {
+    type: "AND" | "OR" | "XOR"
+    inputs: [string, string]
+    output: string
+}
+
+type Input = {
+    inputs: Wire[],
+    gates: Gate[],
+}
+
+const processInput = (day: number) => {
+    const lines = readInputLines(day);
+    let line = lines.shift()!;
+    let inputs: Wire[] = [];
+    while (line !== "") {
+        const [name, value] = line.split(": ");
+        inputs.push({ 
+            name, 
+            value: value === "1" ? "true" : value === "0" ? "false" : "unknown"
+        });
+        line = lines.shift()!;
+    }
+    const gateRegex = /(\w+) (OR|AND|XOR) (\w+) -> (\w+)/;
+    const gates = lines.map(line => {
+        const match = line.match(gateRegex)!;
+        return {
+            type: match[2] as "AND" | "OR" | "XOR",
+            inputs: [match[1], match[3]],
+            output: match[4]
+        };
+    });
+    return { inputs, gates };
+};
+
+const partOne = ({inputs, gates}: Input, debug: boolean) => {
+
+    const wireNames = [...new Set(gates.flatMap(gate => [gate.output, ...gate.inputs]))].toSorted();
+    const wires = wireNames.map(name => {
+        const wire = inputs.find(wire => wire.name === name);
+        return { name, value: wire ? wire.value : "unknown" };
+    });
+
+    let done = wires.every(wire => wire.value !== "unknown");
+    while (!done) {
+        for (const gate of gates) {
+            // is the output known?
+            const outputWire = wires.find(wire => wire.name === gate.output);
+            if (outputWire?.value !== "unknown") {
+                continue;
+            }
+            // are the inputs known?
+            const input1 = wires.find(wire => wire.name === gate.inputs[0])!;
+            const input2 = wires.find(wire => wire.name === gate.inputs[1])!;
+            if (input1?.value === "unknown" || input2?.value === "unknown") {
+                continue;
+            }
+
+            // calculate the output
+            if (gate.type === "AND") {
+                outputWire.value = (input1.value === "true" && input2.value === "true") ? "true" : "false";
+            }
+            if (gate.type === "OR") {
+                outputWire.value = (input1.value === "true" || input2.value === "true") ? "true" : "false";
+            }
+            if (gate.type === "XOR") {
+                outputWire.value = (input1.value !== input2.value) ? "true" : "false";
+            }
+        }
+        done = wires.every(wire => wire.value !== "unknown");
+    }
+
+    const zvalue = wires.filter(wire => wire.name.startsWith("z")).map(zwire => zwire.value === "true" ? 1 : 0).toReversed();
+
+    let result = 0;
+    for (const value of zvalue) {
+        result = result * 2 + value;
+    }
+
+    return result;
+};
+
+const partTwo = (input: Input, debug: boolean) => {
+    if (debug) {
+        console.log("-------Debug-----");
+    }
+    return -1;
+};
+
+const resultOne = (_: any, result: number) => {
+    return `Result part one is ${result}`;
+};
+
+const resultTwo = (_: any, result: number) => {
+    return `Result part two is ${result}`;
+};
+
+const showInput = (input: Input) => {
+    console.log(input);
+};
+
+const test = (_: Input) => {
+    console.log("----Test-----");
+};
+
+export const solution: Puzzle<Input, number> = {
+    day: 24,
+    input: () => processInput(24),
+    partOne,
+    //partTwo,
+    resultOne: resultOne,
+    resultTwo: resultTwo,
+    showInput,
+    test,
+}