[2024/13] Claw Contraption (Part 2)

pfolta · Dec 13, 2024 · 31d39c7 · 31d39c7
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diff --git a/README.md b/README.md
@@ -28,7 +28,7 @@
 |     2021 |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★    |   ★    |        |   ★    |   ★    |        |        |        |        |        |        |        |        |        |        |        |    26 |
 |     2022 |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★    |   ★    |   ★    |   ★    |        |        |        |        |        |        |        |   ☆    |        |        |        |   ☆    |    28 |
 |     2023 |   ★   |   ★   |   ★   |   ★   |   ☆   |   ★   |   ☆   |       |       |        |        |        |        |        |        |        |        |        |        |        |        |        |        |        |        |    12 |
-|     2024 |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★    |   ★    |   ★    |   ☆    |        |        |        |        |        |        |        |        |        |        |        |        |    25 |
+|     2024 |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★   |   ★    |   ★    |   ★    |   ★    |        |        |        |        |        |        |        |        |        |        |        |        |    26 |
 
 ## 🛷 How to run
 
@@ -176,7 +176,7 @@ e.g. `HandyHaversacks`)*
 |                                           |  10 | [Hoof It](https://adventofcode.com/2024/day/10)                                                        | [[Code](src/main/kotlin/adventofcode/year2024/Day10HoofIt.kt)]&nbsp;[[Test](src/test/kotlin/adventofcode/year2024/Day10HoofItSpec.kt)]                                                       | `746`                  | `1541`                                           |
 |                                           |  11 | [Plutonian Pebbles](https://adventofcode.com/2024/day/11)                                              | [[Code](src/main/kotlin/adventofcode/year2024/Day11PlutonianPebbles.kt)]&nbsp;[[Test](src/test/kotlin/adventofcode/year2024/Day11PlutonianPebblesSpec.kt)]                                   | `194482`               | `232454623677743`                                |
 |                                           |  12 | [Garden Groups](https://adventofcode.com/2024/day/12)                                                  | [[Code](src/main/kotlin/adventofcode/year2024/Day12GardenGroups.kt)]&nbsp;[[Test](src/test/kotlin/adventofcode/year2024/Day12GardenGroupsSpec.kt)]                                           | `1573474`              | `966476`                                         |
-|                                           |  13 | [Claw Contraption](https://adventofcode.com/2024/day/13)                                               | [[Code](src/main/kotlin/adventofcode/year2024/Day13ClawContraption.kt)]&nbsp;[[Test](src/test/kotlin/adventofcode/year2024/Day13ClawContraptionSpec.kt)]                                     | `28138`                |                                                  |
+|                                           |  13 | [Claw Contraption](https://adventofcode.com/2024/day/13)                                               | [[Code](src/main/kotlin/adventofcode/year2024/Day13ClawContraption.kt)]&nbsp;[[Test](src/test/kotlin/adventofcode/year2024/Day13ClawContraptionSpec.kt)]                                     | `28138`                | `108394825772874`                                |
 
 ## 🕯️ Useful commands
 

diff --git a/src/main/kotlin/adventofcode/common/Grid2d.kt b/src/main/kotlin/adventofcode/common/Grid2d.kt
@@ -3,9 +3,11 @@ package adventofcode.common
 import kotlin.String
 
 data class Point2d(
-    val x: Int,
-    val y: Int,
+    val x: Long,
+    val y: Long,
 ) {
+    constructor(x: Number, y: Number) : this(x.toLong(), y.toLong())
+
     /**
      * Pretty formatted String representation.
      *
@@ -17,6 +19,11 @@ data class Point2d(
      * Add two points together by adding their x and y coordinates
      */
     operator fun plus(other: Point2d): Point2d = Point2d(x + other.x, y + other.y)
+
+    /**
+     * Add a constant offset to the point's x and y coordinates
+     */
+    operator fun plus(offset: Number): Point2d = Point2d(x + offset.toLong(), y + offset.toLong())
 }
 
 val NORTH = Point2d(0, -1)
@@ -56,19 +63,23 @@ data class Grid2d<T>(val values: List<List<T>>) {
      */
     fun find(value: T): List<Point2d> =
         points
-            .filter { (x, y) -> values[y][x] == value }
+            .filter { (x, y) -> values[y.toInt()][x.toInt()] == value }
             .map { (x, y) -> Point2d(x, y) }
 
     /**
      * Returns the value at the given point if the point is within the grid, throws otherwise.
      */
     operator fun get(point: Point2d): T =
-        if (point in this) values[point.y][point.x] else throw IndexOutOfBoundsException("Point $point is not part of this grid")
+        if (point in this) {
+            values[point.y.toInt()][point.x.toInt()]
+        } else {
+            throw IndexOutOfBoundsException("Point $point is outside of the grid")
+        }
 
     /**
      * Returns the value at the given point if the point is within the grid, or `null` otherwise.
      */
-    fun getOrNull(point: Point2d): T? = if (point in this) values[point.y][point.x] else null
+    fun getOrNull(point: Point2d): T? = if (point in this) values[point.y.toInt()][point.x.toInt()] else null
 
     /**
      * Returns a set of valid neighbors for a given point P in the grid.

diff --git a/src/main/kotlin/adventofcode/year2024/Day13ClawContraption.kt b/src/main/kotlin/adventofcode/year2024/Day13ClawContraption.kt
@@ -21,9 +21,27 @@ class Day13ClawContraption(customInput: PuzzleInput? = null) : Puzzle(customInpu
             }
     }
 
-    override fun partOne() =
+    override fun partOne() = clawMachines.sumOf { clawMachine -> clawMachine.countTokens() }
+
+    override fun partTwo() =
         clawMachines
-            .mapNotNull { (buttonA, buttonB, prize) ->
+            .map { (buttonA, buttonB, prize) -> ClawMachine(buttonA, buttonB, prize + PART_TWO_OFFSET) }
+            .sumOf { clawMachine -> clawMachine.countTokens() }
+
+    companion object {
+        private val INPUT_REGEX = """X[+|=](\d+), Y[+|=](\d+)""".toRegex()
+
+        private const val COST_A = 3
+        private const val COST_B = 1
+
+        private const val PART_TWO_OFFSET = 10000000000000
+
+        private data class ClawMachine(
+            val buttonA: Point2d,
+            val buttonB: Point2d,
+            val prize: Point2d,
+        ) {
+            fun countTokens(): Long {
                 val (ax, ay) = buttonA
                 val (bx, by) = buttonB
                 val (px, py) = prize
@@ -32,24 +50,12 @@ class Day13ClawContraption(customInput: PuzzleInput? = null) : Puzzle(customInpu
                 val a = px * by - bx * py
                 val b = ax * py - px * ay
 
-                if (setOf(a, b).all { it % dividend == 0 }) {
+                return if (setOf(a, b).all { it % dividend == 0L }) {
                     a / dividend * COST_A + b / dividend * COST_B
                 } else {
-                    null
+                    0
                 }
             }
-            .sum()
-
-    companion object {
-        private val INPUT_REGEX = """X[+|=](\d+), Y[+|=](\d+)""".toRegex()
-
-        private const val COST_A = 3
-        private const val COST_B = 1
-
-        private data class ClawMachine(
-            val buttonA: Point2d,
-            val buttonB: Point2d,
-            val prize: Point2d,
-        )
+        }
     }
 }
diff --git a/src/test/kotlin/adventofcode/common/Grid2dSpec.kt b/src/test/kotlin/adventofcode/common/Grid2dSpec.kt
@@ -85,7 +85,7 @@ class Grid2dSpec : FreeSpec({
             shouldThrow<IndexOutOfBoundsException> {
                 grid[Point2d(10, 10)]
             }.apply {
-                message shouldBe "Point (10, 10) is not part of this grid"
+                message shouldBe "Point (10, 10) is outside of the grid"
             }
         }
     }