Day 18 part 1 solution

input/day18_test

@@ -0,0 +1,13 @@
+2,2,2
+1,2,2
+3,2,2
+2,1,2
+2,3,2
+2,2,1
+2,2,3
+2,2,4
+2,2,6
+1,2,5
+3,2,5
+2,1,5
+2,3,5

src/day18/solution1/App.kt

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+package day18
+
+// Original solution used to solve the AoC day 18 puzzle.
+
+import common.Solution
+
+data class Vec3(val x: Int, val y: Int, val z: Int) {
+    operator fun plus(v: Vec3): Vec3 = Vec3(this.x + v.x, this.y + v.y, this.z + v.z)
+    override fun toString(): String = "($x, $y, $z)"
+}
+
+val Directions: List<Vec3> = listOf(
+    Vec3(1, 0, 0),
+    Vec3(0, 1, 0),
+    Vec3(0, 0, 1),
+    Vec3(-1, 0, 0),
+    Vec3(0, -1, 0),
+    Vec3(0, 0, -1),
+)
+
+typealias Point = Vec3
+
+typealias ParsedInput = List<Vec3>
+
+object Day18 : Solution.LinedInput<ParsedInput>(day = 18) {
+
+    override fun parseInput(input: List<String>): ParsedInput {
+        return input.map{ line ->
+            line.split(',').map(String::toInt).let { (x, y, z) -> Vec3(x, y, z) }
+        }
+    }
+
+    override fun part1(input: ParsedInput): Any {
+        val cubes = input.toSet()
+        val exposedFaces = cubes.fold(0) { count, cube ->
+            count + Directions.count { dir -> (cube + dir) !in cubes }
+        }
+        return exposedFaces
+    }
+
+    override fun part2(input: ParsedInput): Any {
+        return Unit
+    }
+}
+
+fun main() {
+    Day18.solve(test = false)
+}