day 4 puzzle 2

README.md

@@ -5,11 +5,11 @@ This repo contains my attempt at this year's Advent of Code (2023)
 I will try and do some problems (probably not all of them) in Scala
 
 ## Progress:
-#### Stars: 6 / 50
+#### Stars: 8 / 50
 |        Mon        | Tue | Wed | Thu |        Fri        |        Sat        |        Sun        |
-|:---:|:---:|:---:|:---:|:-----------------:|:-----------------:|:-----------------:|
+|:-----------------:|:---:|:---:|:---:|:-----------------:|:-----------------:|:-----------------:|
 |                   |     |     |     | 1<br>:star::star: | 2<br>:star::star: | 3<br>:star::star: |
-|  4  |  5  |  6  |  7  |         8         |         9         |        10         |
+| 4<br>:star::star: |  5  |  6  |  7  |         8         |         9         |        10         |
 |        11         | 12  | 13  | 14  |        15         |        16         |        17         |
 |        18         | 19  | 20  | 21  |        22         |        23         |        24         |
 |        25         |     |     |     |                   |                   |                   |

src/day4/Puzzle1.scala

@@ -0,0 +1,44 @@
+package day4
+
+import scala.io.{BufferedSource, Source}
+
+object Puzzle1 {
+  case class Card(validNumbers: Array[Int], myNumbers: Array[Int])
+
+  var cards: Array[Card] = Array.empty
+
+  def loadInput(path: String): Unit = {
+    val source: BufferedSource = Source.fromFile(path)
+
+    val lines: Array[String] = source.getLines().toArray
+    cards = new Array(lines.length)
+
+    for ((line: String, i: Int) <- lines.zipWithIndex) {
+      val parts: Array[String] = line.split(": +")(1).split(" +\\| +")
+      val validNumbers: Array[Int] = parts(0).split(" +").map(n => n.toInt)
+      val myNumbers: Array[Int] = parts(1).split(" +").map(n => n.toInt)
+      cards(i) = Card(validNumbers, myNumbers)
+    }
+
+    source.close()
+  }
+
+  def computeGain(): Int = {
+    var gain: Int = 0
+    for (card: Card <- cards) {
+      val validCount: Int = card.validNumbers.intersect(card.myNumbers).length
+      if (validCount >= 1) {
+        gain += Math.pow(2, validCount-1).toInt
+      }
+    }
+    return gain
+  }
+  def solve(path: String): Int = {
+    loadInput(path)
+    return computeGain()
+  }
+  def main(args: Array[String]): Unit = {
+    val solution: Int = solve("res/day4/input1.txt")
+    println(solution)
+  }
+}

src/day4/Puzzle2.scala

@@ -0,0 +1,48 @@
+package day4
+
+import scala.collection.mutable
+import scala.io.{BufferedSource, Source}
+
+object Puzzle2 {
+  case class Card(id: Int, validNumbers: Array[Int], myNumbers: Array[Int], var score: Int = 0, var count: Int = 1)
+
+  var cards: Array[Card] = Array.empty
+
+  def loadInput(path: String): Unit = {
+    val source: BufferedSource = Source.fromFile(path)
+
+    val lines: Array[String] = source.getLines().toArray
+    cards = new Array(lines.length)
+
+    for ((line: String, i: Int) <- lines.zipWithIndex) {
+      val parts: Array[String] = line.split(": +")(1).split(" +\\| +")
+      val validNumbers: Array[Int] = parts(0).split(" +").map(n => n.toInt)
+      val myNumbers: Array[Int] = parts(1).split(" +").map(n => n.toInt)
+      cards(i) = Card(i, validNumbers, myNumbers)
+    }
+
+    source.close()
+  }
+
+  def computeScores(): Unit = {
+    for (card: Card <- cards) {
+      card.score = card.validNumbers.intersect(card.myNumbers).length
+    }
+  }
+  def solve(path: String): Int = {
+    loadInput(path)
+    computeScores()
+    var count: Int = 0
+    for (card: Card <- cards) {
+      count += card.count
+      for (i: Int <- 0 until card.score) {
+        cards(card.id + i + 1).count += card.count
+      }
+    }
+    return count
+  }
+  def main(args: Array[String]): Unit = {
+    val solution: Int = solve("res/day4/input1.txt")
+    println(solution)
+  }
+}

tests/day4/Puzzle1Test.scala

@@ -0,0 +1,9 @@
+package day4
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class Puzzle1Test extends AnyFunSuite {
+  test("Puzzle1.solve") {
+    assert(Puzzle1.solve("tests_res/day4/input1.txt") == 13)
+  }
+}

tests/day4/Puzzle2Test.scala

@@ -0,0 +1,9 @@
+package day4
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class Puzzle2Test extends AnyFunSuite {
+  test("Puzzle2.solve") {
+    assert(Puzzle2.solve("tests_res/day4/input1.txt") == 30)
+  }
+}

tests_res/day4/input1.txt

@@ -0,0 +1,6 @@
+Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11