day 3

.github/workflows/checks.yaml

@@ -23,7 +23,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: denoland/setup-deno@v2
-      - run: deno test --junit-path=./junit.xml
+      - run: deno test --allow-read --parallel --junit-path=./junit.xml
       - uses: EnricoMi/publish-unit-test-result-action@v2
         if: always()
         with:

cli.ts

@@ -2,7 +2,7 @@ import { colors } from "@cliffy/ansi/colors";
 import { Command } from "@cliffy/command";
 import { Input, Select } from "@cliffy/prompt";
 import { readLinesFromFile } from "utils";
-import { days, getSolution } from "./days/mod.ts";
+import { days } from "./days/mod.ts";
 import denoJson from "./deno.json" with { type: "json" };
 import {
   readLinesFromStdin,
@@ -13,7 +13,7 @@ const list = new Command()
   .description("List all available solutions")
   .action(() => {
     console.log("Available solutions:");
-    for (const day of Object.keys(days)) {
+    for (const day of days.keys()) {
       console.log(`- ${day}`);
     }
   });
@@ -22,7 +22,7 @@ const main = new Command()
   .name("Advent of Code - 2024")
   .version(denoJson.version)
   .description("...")
-  .option("-d, --day <day:string>", "Day to run")
+  .option("-d, --day <day:number>", "Day to run")
   .option("-i, --input <input:file>", "Input file, local path or remote URL")
   .action(async (options) => {
     let input: Array<string> | null = null;
@@ -43,7 +43,7 @@ const main = new Command()
       Deno.exit(1);
     }
     const day = options.day ?? await selectDay();
-    const solution = getSolution(day);
+    const solution = days.get(day);
     if (solution == null) {
       console.error(`Day ${day} not found`);
       Deno.exit(1);
@@ -60,11 +60,11 @@ async function provideInput(): Promise<string> {
   });
 }
 
-async function selectDay(): Promise<string> {
+async function selectDay(): Promise<number> {
   return await Select.prompt({
     message: "Select day",
-    options: Object.keys(days).map((day) => ({
-      name: day.toString().padStart(2, "0"),
+    options: [...days.keys()].map((day) => ({
+      name: day.toString(),
       value: day,
     })),
   });

days/1/main_test.ts

@@ -0,0 +1,33 @@
+import { expect } from "@std/expect";
+import { describe, it } from "@std/testing/bdd";
+import { part1, part2 } from "./main.ts";
+import { loadInput } from "utils";
+
+describe("day 1 example", () => {
+  const input = [
+    "3   4",
+    "4   3",
+    "2   5",
+    "1   3",
+    "3   9",
+    "3   3",
+  ];
+
+  it("part 1", () => {
+    expect(part1(input)).toBe(11);
+  });
+
+  it("part 2", () => {
+    expect(part2(input)).toBe(31);
+  });
+});
+
+describe("day 1 solution", () => {
+  it("part 1", async () => {
+    expect(part1(await loadInput(1))).toBe(2378066);
+  });
+
+  it("part 2", async () => {
+    expect(part2(await loadInput(1))).toBe(18934359);
+  });
+});

days/2/main_test.ts

@@ -0,0 +1,33 @@
+import { expect } from "@std/expect";
+import { describe, it } from "@std/testing/bdd";
+import { part1, part2 } from "./main.ts";
+import { loadInput } from "utils";
+
+describe("day 2 example", () => {
+  const input = [
+    "7 6 4 2 1",
+    "1 2 7 8 9",
+    "9 7 6 2 1",
+    "1 3 2 4 5",
+    "8 6 4 4 1",
+    "1 3 6 7 9",
+  ];
+
+  it("part 1", () => {
+    expect(part1(input)).toBe(2);
+  });
+
+  it("part 2", () => {
+    expect(part2(input)).toBe(4);
+  });
+});
+
+describe("day 2 solution", () => {
+  it("part 1", async () => {
+    expect(part1(await loadInput(2))).toBe(421);
+  });
+
+  it("part 2", async () => {
+    expect(part2(await loadInput(2))).toBe(476);
+  });
+});

days/3/main.ts

@@ -0,0 +1,59 @@
+import { loadInput } from "utils";
+
+type Mul = readonly [number, number];
+
+export function part1(input: Array<string>) {
+  return [...getAllMuls(input.join("|"))].map(([a, b]) => a * b).reduce(
+    (acc, n) => acc + n,
+    0,
+  );
+}
+
+export function part2(input: Array<string>) {
+  return [...getAllConditionalMuls(input.join("|"))].map(([a, b]) => a * b)
+    .reduce(
+      (acc, n) => acc + n,
+      0,
+    );
+}
+
+function matchMul(input: string): [Mul, string, number] | null {
+  const match = input.match(/mul\((\d{1,3}),(\d{1,3})\)/);
+  if (match == null) return null;
+  const remaining = input.slice(match.index! + match[0].length);
+  return [
+    [parseInt(match[1], 10), parseInt(match[2], 10)],
+    remaining,
+    match.index!,
+  ];
+}
+
+function* getAllMuls(input: string) {
+  let remaining = input;
+  while (true) {
+    const match = matchMul(remaining);
+    if (match == null) {
+      break;
+    }
+    yield match[0];
+    remaining = match[1];
+  }
+}
+
+function* getAllConditionalMuls(input: string) {
+  const doables = input.split("do()");
+  for (let doable of doables) {
+    const indexOfDont = doable.indexOf("don't()");
+    if (indexOfDont !== -1) {
+      doable = doable.slice(0, indexOfDont);
+    }
+    for (const mul of getAllMuls(doable)) {
+      yield mul;
+    }
+  }
+}
+
+if (import.meta.main) {
+  console.log(part1(await loadInput(3)));
+  console.log(part2(await loadInput(3)));
+}

days/3/main_test.ts

@@ -0,0 +1,32 @@
+import { expect } from "@std/expect";
+import { describe, it } from "@std/testing/bdd";
+import { part1, part2 } from "./main.ts";
+import { loadInput } from "utils";
+
+describe("day 3 example", () => {
+  it("part 1", () => {
+    expect(
+      part1([
+        "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))",
+      ]),
+    ).toBe(161);
+  });
+
+  it("part 2", () => {
+    expect(
+      part2([
+        "xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))",
+      ]),
+    ).toBe(48);
+  });
+});
+
+describe("day 3 solution", () => {
+  it("part 1", async () => {
+    expect(part1(await loadInput(3))).toBe(162813399);
+  });
+
+  it("part 2", async () => {
+    expect(part2(await loadInput(3))).toBe(53783319);
+  });
+});

days/mod.ts

@@ -1,18 +1,10 @@
 type PartFunction = (input: Array<string>) => number;
 type Solution = { part1: PartFunction; part2: PartFunction };
 
-const days: Record<string, Solution> = {};
+const days = new Map<number, Solution>();
 
-for (const day of [1, 2]) {
-  days[pad(day)] = await import(`./${pad(day)}/main.ts`);
-}
-
-export function getSolution(day: string | number): Solution | null {
-  return days[pad(day)];
+for (const day of [1, 2, 3]) {
+  days.set(day, await import(`./${day}/main.ts`));
 }
 
 export { days };
-
-function pad(day: string | number) {
-  return day.toString().padStart(2, "0");
-}

deno.json

@@ -14,6 +14,7 @@
     "@std/collections": "jsr:@std/collections@1",
     "@std/path": "jsr:@std/path@1",
     "@std/streams": "jsr:@std/streams@^1.0.8",
+    "@std/testing": "jsr:@std/testing@^1.0.5",
     "utils": "./utils/mod.ts"
   }
 }

utils/loadInput.ts

@@ -6,7 +6,7 @@ export function loadInput(day: number): Promise<Array<string>> {
     dirname(fromFileUrl(import.meta.url)),
     "..",
     "inputs",
-    `${day.toString().padStart(2, "0")}.txt`,
+    `${day}.txt`,
   );
   return readLinesFromFile(path);
 }