expeditaet/solutions/typescript/2021/15/src/p1.ts

Advent of Code Solutions

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

export const p1 = (input: string): number => {
	const graph = input.toGridGraph<number>({
		valueConverter: (s) => Number.parseInt(s, 10),
		weighter: (a, b) => b.value - a.value,
		connectionDirections: Direction.cardinalDirections,
	});

	const boundingBox = graph.boundingBox();
	const start = graph.getNode(boundingBox.topLeft);
	const end = graph.getNode(boundingBox.bottomRight);

	if (!start) {
		throw new Error('Start node does not exist');
	}

	const { path } = graph.aStar({
		start,
		end,
		heuristic: (_currentNode, tentativePath) => tentativePath.map((n) => n.value).sum(),
	});

	return path.map((p) => p.value).sum() - (start?.value ?? 0);
};

await task(p1, packageJson.aoc); // 609 ~153.42ms