2025: Day 1

AdventOfCode2025/day1/index.ts

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+const file = Bun.file("./input.txt");
+const content = await file.text();
+
+const turns = content
+	.trim()
+	.split("\n")
+	.map((l) => Number(l[0] === "L" ? -1 : 1) * Number(l.slice(1)));
+
+let part1 = 0;
+let part2 = 0;
+let position = 50;
+
+for (const turn of turns) {
+	const effectiveTurn = turn % 100;
+	const boundToAdd = position === 0 ? 0 : 1;
+
+	position += effectiveTurn;
+
+	if (position > 99) {
+		position = position - 100;
+		part2 += boundToAdd;
+	} else if (position < 0) {
+		position = 100 + position;
+		part2 += boundToAdd;
+	} else if (position === 0) {
+		part2 += boundToAdd;
+	}
+
+	const fullTurns = Math.floor(Math.abs(turn) / 100);
+	part2 += fullTurns;
+
+	if (position === 0) {
+		part1++;
+	}
+}
+
+console.log("Part 1: ", part1);
+console.log("Part 2: ", part2);