From ece85a2e997a162b4218f075c5d87cfed77ae85a Mon Sep 17 00:00:00 2001
From: Julien Dessaux
Date: Tue, 27 Dec 2022 22:42:42 +0100
Subject: 2022-18 in js

---
 2022/18-Boiling-Boulders/second.js | 63 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 2022/18-Boiling-Boulders/second.js

(limited to '2022/18-Boiling-Boulders/second.js')

diff --git a/2022/18-Boiling-Boulders/second.js b/2022/18-Boiling-Boulders/second.js
new file mode 100644
index 0000000..a1f57a7
--- /dev/null
+++ b/2022/18-Boiling-Boulders/second.js
@@ -0,0 +1,63 @@
+import * as fs from "fs";
+
+function load(filename) {
+	return fs.readFileSync(filename, "utf8")
+		.trim()
+		.split("\n");
+}
+
+let example = load("example");
+let input = load("input");
+
+function countSides(x, y, z, input) {
+	let count = 0;
+	if (input.includes([x+1, y, z].join(","))) count++;
+	if (input.includes([x-1, y, z].join(","))) count++;
+	if (input.includes([x, y+1, z].join(","))) count++;
+	if (input.includes([x, y-1, z].join(","))) count++;
+	if (input.includes([x, y, z+1].join(","))) count++;
+	if (input.includes([x, y, z-1].join(","))) count++;
+	return count;
+}
+
+function solve(input) {
+	// compute the boundaries of the playing field
+	let min = Infinity;
+	let max = -Infinity;
+	input.forEach(line => {
+		let [x, y, z] = line.split(",").map(n => parseInt(n));
+		min = Math.min(min, x, y, z);
+		max = Math.max(max, x, y, z);
+	})
+	min -=1;
+	max +=1;
+	// start with an edge and fill up the space
+	let count = 0;
+	let queue = [[min, min, min]];
+	let visited = new Set();
+	while (queue.length > 0) {
+		const elt = queue.shift();
+		const eltstr = elt.join(",");
+		const [x, y, z] = elt;
+		if (x < min || x > max || y < min || y > max || z < min || z > max) continue;
+		if (visited.has(eltstr)) continue
+		if (input.includes(eltstr)) continue;
+		visited.add(eltstr);
+		count += countSides(x, y, z, input);
+		queue.push([x+1, y, z]);
+		queue.push([x-1, y, z]);
+		queue.push([x, y+1, z]);
+		queue.push([x, y-1, z]);
+		queue.push([x, y, z+1]);
+		queue.push([x, y, z-1]);
+	}
+	return count;
+}
+
+const exampleOutput = solve(example);
+if (exampleOutput !== 58) {
+	console.log("Example failed with " + exampleOutput);
+	process.exit(1); // eslint-disable-line
+}
+
+console.log(solve(input));
-- 
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