Add day 18

Author: LiquidFun

2022/18/18.kt

@@ -0,0 +1,39 @@
+data class Point(var x: Int, var y: Int, var z: Int) {
+	operator fun plus(o: Point): Point = Point(x+o.x, y+o.y, z+o.z)
+	fun adjacent(): List<Point> = dirs.map { this+it }.toList()
+}
+
+val dirs = listOf(
+	Point(1, 0, 0), Point(0, 1, 0), Point(0, 0, 1),
+	Point(-1, 0, 0), Point(0, -1, 0), Point(0, 0, -1),
+)
+
+fun main() {
+	val input = generateSequence(::readlnOrNull)
+		.map { it.split(",").map { it.toInt() } }
+		.map { (x, y, z) -> Point(x, y, z) }.toList()
+	val limitsX = input.minOf { it.x-1 }..input.maxOf { it.x+1 }
+	val limitsY = input.minOf { it.y-1 }..input.maxOf { it.y+1 }
+	val limitsZ = input.minOf { it.z-1 }..input.maxOf { it.z+1 }
+	
+	// Part 1
+	input.sumOf { it.adjacent().count { !input.contains(it) } }.run(::println)
+
+	// Part 2
+	val queue = ArrayDeque<Point>()
+	queue.add(Point(limitsX.first, limitsY.first, limitsZ.first))
+	var count = 0
+	val visited: MutableSet<Point> = mutableSetOf()
+	while (queue.isNotEmpty()) {
+		val point = queue.removeFirst()
+		if (point in visited) continue
+		visited.add(point)
+		for (adj in point.adjacent()) {
+			if (adj in input) 
+				count++
+			else if (adj.x in limitsX && adj.y in limitsY && adj.z in limitsZ)
+				queue.add(adj)
+		}
+	}
+	println(count)
+}

2022/18/input.ans

@@ -0,0 +1,2 @@
+3448
+2052