day 2

day-1/day1-part1.ts

@@ -1,4 +1,5 @@
 import * as path from 'path'
+import {sum, zipWith} from 'remeda'
 
 export async function day1Part1() {
     const input = await Bun.file(path.join(__dirname, 'input.txt')).text()
@@ -23,6 +24,7 @@ export async function day1Part1() {
         const diff = Math.abs(left - right)
         result += diff
     }
+    const foo = sum(zipWith(column1, column2, (a, b) => Math.abs(a - b)))
 
-    console.log({result})
+    console.log({result, foo})
 }

day-2/day2.test.ts

@@ -0,0 +1,43 @@
+import { expect, test } from "bun:test";
+import * as path from "node:path";
+import { day2, day2part2 } from "./day2.ts";
+
+test("day 2, part 1", async () => {
+	const testInput = await Bun.file(
+		path.resolve(__dirname, "test-input.txt"),
+	).text();
+	const input = await Bun.file(path.resolve(__dirname, "input.txt")).text();
+
+	const [testResult, finalResult] = await Promise.all([
+		day2(testInput),
+		day2(input),
+	]);
+
+	console.log("\n\n");
+	console.log("Test data:", testResult);
+	console.log("Full data:", finalResult);
+	console.log("\n\n");
+
+	expect(testResult).toEqual(2);
+	expect(finalResult).toEqual(359);
+});
+
+test("day 2, part 2", async () => {
+	const testInput = await Bun.file(
+		path.resolve(__dirname, "test-input.txt"),
+	).text();
+	const input = await Bun.file(path.resolve(__dirname, "input.txt")).text();
+
+	const [testResult, finalResult] = await Promise.all([
+		day2part2(testInput),
+		day2part2(input),
+	]);
+
+	console.log("\n\n");
+	console.log("Test data:", testResult);
+	console.log("Full data:", finalResult);
+	console.log("\n\n");
+
+	expect(testResult).toEqual(4);
+	expect(finalResult).toEqual(418);
+});

day-2/day2.ts

@@ -0,0 +1,76 @@
+export async function day2(input: string) {
+	const lines = input.split("\n");
+	let count = 0;
+	for (const line of lines) {
+		const levels = line.split(" ").map((v) => Number.parseInt(v, 10));
+		const safe = isSafe(levels);
+
+		if (safe) {
+			count++;
+		}
+	}
+	return count;
+}
+
+export async function day2part2(input: string) {
+	const lines = input.split("\n");
+	let count = 0;
+	for (const line of lines) {
+		const levels = line.split(" ").map((v) => Number.parseInt(v, 10));
+		const isFullySafe = isSafe(levels);
+
+		if (isFullySafe) {
+			count++;
+			continue;
+		}
+
+		let isDampenedSafe = false;
+
+		for (let i = 0; i < levels.length; i++) {
+			const toTry = levels.toSpliced(i, 1);
+
+			if (isSafe(toTry)) {
+				isDampenedSafe = true;
+				break;
+			}
+		}
+
+		if (isDampenedSafe) {
+			count++;
+		}
+	}
+
+	return count;
+}
+
+function isSafe(levels: number[]) {
+	let increasing = null;
+	let safe = true;
+
+	for (let i = 0; i < levels.length - 1; i++) {
+		const current = levels[i];
+		const next = levels[i + 1];
+		const diff = Math.abs(next - current);
+
+		if (diff > 3 || diff < 1) {
+			safe = false;
+			break;
+		}
+
+		if (i === 0) {
+			increasing = next > current;
+			continue;
+		}
+
+		if (increasing && next <= current) {
+			safe = false;
+			break;
+		}
+
+		if (!increasing && next >= current) {
+			safe = false;
+			break;
+		}
+	}
+	return safe;
+}

day-2/test-input.txt

@@ -0,0 +1,6 @@
+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

index.ts

@@ -1,4 +0,0 @@
-import {day1Part1} from "./day-1/day1-part1.ts";
-import {day1Part2} from "./day-1/day1-part2.ts";
-
-await day1Part2()