part1.ts

import * as fs from 'fs';

const input = fs.readFileSync('input', 'utf8').split('\n').map((x) => x.split(''));

const rows = input.length;
const columns = input[0].length;
const shifts = [
	[0, 1],
	[1, 0],
	[0, -1],
	[-1, 0],
];
const startingRow = input.findIndex((x) => x.includes('S'));
const queue = [[startingRow, input[startingRow].indexOf('S')]];

for (let i = 0; i < 64; i++) {
	const prevQueue = [...queue];
	const queueSet = new Set();
	queue.length = 0;

	while (prevQueue.length > 0) {
		const pos = prevQueue.shift();

		for (const shift of shifts) {
			const row = pos[0] + shift[0];
			const column = pos[1] + shift[1];
			const nextPos = [row, column];
			if (
				row >= 0 &&
				column >= 0 &&
				row < columns &&
				column < rows &&
				input[row][column] !== '#' &&
				!queueSet.has(nextPos.join(','))
			) {
				queueSet.add(nextPos.join(','));
				queue.push(nextPos);
			}
		}
	}
}

console.log(queue.length);