92 lines
2.8 KiB
TypeScript
92 lines
2.8 KiB
TypeScript
import { BinaryHeap } from "jsr:@std/data-structures/binary-heap";
|
|
|
|
export type Input = {
|
|
fallingBytes: [number, number][];
|
|
};
|
|
|
|
export async function readData(path: string): Promise<Input> {
|
|
const lines = await Deno.readTextFile(path);
|
|
const fallingBytes = lines.split("\n").map((line) => {
|
|
const [a, b] = line.trim().split(",").map((x) => parseInt(x));
|
|
return [a, b] as [number, number];
|
|
});
|
|
return { fallingBytes };
|
|
}
|
|
|
|
export function displayMap(map: string[][]) {
|
|
console.log(map.map(x=>x.join("")).join("\n"));
|
|
}
|
|
|
|
export function solvePart(
|
|
map: string[][],
|
|
) {
|
|
const WIDTH = map[0].length;
|
|
const HEIGHT = map.length;
|
|
|
|
const queue = new BinaryHeap<{
|
|
pos: [number, number];
|
|
step: number;
|
|
previous: null | { pos: [number, number]; step: number };
|
|
}>((x,y) => x.step - y.step);
|
|
queue.push({ pos: [0, 0], step: 0, previous: null });
|
|
const visited = new Set<string>();
|
|
const path = new Map<string, { pos: [number, number]; step: number;
|
|
previous: null | { pos: [number, number]; step: number }
|
|
}>();
|
|
|
|
while (queue.length > 0) {
|
|
const node = queue.pop()!;
|
|
const { pos, step } = node;
|
|
const [x, y] = pos;
|
|
if (x < 0 || x >= WIDTH || y < 0 || y >= HEIGHT) {
|
|
continue;
|
|
}
|
|
if (map[y][x] === "#") {
|
|
continue;
|
|
}
|
|
if (visited.has(`${x},${y}`)) {
|
|
continue;
|
|
}
|
|
visited.add(`${x},${y}`);
|
|
path.set(`${x},${y}`, node);
|
|
if (x === WIDTH - 1 && y === HEIGHT - 1) {
|
|
console.log(step);
|
|
break;
|
|
}
|
|
queue.push({ pos: [x + 1, y], step: step + 1, previous: { pos, step } });
|
|
queue.push({ pos: [x - 1, y], step: step + 1, previous: { pos, step } });
|
|
queue.push({ pos: [x, y + 1], step: step + 1, previous: { pos, step } });
|
|
queue.push({ pos: [x, y - 1], step: step + 1, previous: { pos, step } });
|
|
}
|
|
if (!path.has(`${WIDTH - 1},${HEIGHT - 1}`)) {
|
|
console.log("No path found");
|
|
return;
|
|
}
|
|
let current = path.get(`${WIDTH - 1},${HEIGHT - 1}`)!;
|
|
while (current.previous !== null) {
|
|
const [x, y] = current.pos;
|
|
map[y][x] = "O";
|
|
current = path.get(`${current.previous.pos[0]},${current.previous.pos[1]}`)!;
|
|
|
|
}
|
|
displayMap(map);
|
|
}
|
|
|
|
if (import.meta.main) {
|
|
// const data = await readData("example.txt");
|
|
// const WIDTH = 7;
|
|
// const HEIGHT = 7;
|
|
// const FALLING_BYTES = 12;
|
|
|
|
const data = await readData("input.txt");
|
|
const WIDTH = 71;
|
|
const HEIGHT = 71;
|
|
const FALLING_BYTES = 1024;
|
|
const map = new Array(HEIGHT).fill(0).map(() => new Array(WIDTH).fill("."));
|
|
for (const [x, y] of data.fallingBytes.slice(0,FALLING_BYTES)) {
|
|
map[y][x] = "#";
|
|
}
|
|
displayMap(map);
|
|
solvePart(map);
|
|
}
|