expeditaet/solutions/typescript/2016/01/src/p2.ts

Advent of Code Solutions

import { task } from '@alexaegis/advent-of-code-lib';
import { Direction, Vec2 } from '@alexaegis/advent-of-code-lib/model';
import packageJson from '../package.json';

export const p2 = (input: string): number => {
	const acc = {
		position: Vec2.ORIGIN.clone(),
		direction: Direction.NORTH,
		history: new Set<string>(),
	};
	loop: for (const next of input.split(', ')) {
		if (next.startsWith('R')) acc.direction = acc.direction.right();
		else if (next.startsWith('L')) acc.direction = acc.direction.left();
		for (let i = 0; i < Number(next.slice(1)); i++) {
			acc.position.addMut(acc.direction);
			const coordString = acc.position.toString();
			if (acc.history.has(coordString)) break loop;
			acc.history.add(coordString);
		}
	}
	return acc.position.manhattan(Vec2.ORIGIN);
};

await task(p2, packageJson.aoc); // 159 ~0.48ms