day 5

day-5/day5.test.ts

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+import { expect, test } from "bun:test";
+import * as path from "node:path";
+import { day5, day5part2 } from "./day5.ts";
+
+test("day 5, 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 = day5(testInput);
+	const finalResult = day5(input);
+	console.log("\n\n");
+	console.log("Test data:", testResult);
+	console.log("Full data:", finalResult);
+	console.log("\n\n");
+
+	expect(testResult).toEqual(143);
+	expect(finalResult).toEqual(5588);
+});
+
+test("day 5, 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 = day5part2(testInput);
+	console.log("\n\n");
+	console.log("Test data:", testResult);
+	const finalResult = day5part2(input);
+	console.log("Full data:", finalResult);
+	expect(finalResult).toEqual(5331);
+
+	console.log("\n\n");
+
+	expect(testResult).toEqual(123);
+});

day-5/day5.ts

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+export function day5(input: string) {
+	let result = 0;
+
+	const [rulesStr, updatesStr] = input.split("\n\n");
+
+	const rules = rulesStr.split("\n").map((x) => x.split("|"));
+	const updates = updatesStr.split("\n").map((x) => x.split(","));
+
+	for (const update of updates) {
+		let isValid = true;
+		for (let i = 0; i < rules.length; i++) {
+			const rule = rules[i];
+			const x = rule[0];
+			const y = rule[1];
+			const xIndex = update.indexOf(x);
+			const yIndex = update.indexOf(y);
+			if (xIndex === -1 || yIndex === -1) {
+				continue;
+			}
+			if (yIndex < xIndex) {
+				console.log("not valid", {
+					x,
+					y,
+					xIndex,
+					yIndex,
+					update,
+				});
+				isValid = false;
+				break;
+			}
+		}
+
+		if (isValid) {
+			const middleValue = update[Math.floor(update.length / 2)];
+			result += Number.parseInt(middleValue);
+		}
+	}
+
+	return result;
+}
+
+export function day5part2(input: string) {
+	let result = 0;
+
+	const [rulesStr, updatesStr] = input.split("\n\n");
+
+	const rules = rulesStr.split("\n").map((x) => x.split("|"));
+	const updates = updatesStr.split("\n").map((x) => x.split(","));
+
+	const invalidUpdates = [];
+	for (const update of updates) {
+		let isValid = true;
+		for (let i = 0; i < rules.length; i++) {
+			const rule = rules[i];
+			const x = rule[0];
+			const y = rule[1];
+			const xIndex = update.indexOf(x);
+			const yIndex = update.indexOf(y);
+			if (xIndex === -1 || yIndex === -1) {
+				continue;
+			}
+			if (yIndex < xIndex) {
+				isValid = false;
+				break;
+			}
+		}
+
+		if (!isValid) {
+			invalidUpdates.push(update);
+		}
+	}
+
+	for (const update of invalidUpdates) {
+		update.sort((a, b) => {
+			const rule = rules.find((v) => v.includes(a) && v.includes(b));
+			if (!rule) {
+				return 0;
+			}
+			if (rule[0] === a) {
+				return -1;
+			}
+			return 1;
+		});
+		const middleValue = update[Math.floor(update.length / 2)];
+		result += Number.parseInt(middleValue);
+	}
+
+	return result;
+}

day-5/test-input.txt

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+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47