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: 7 / 50
+#### Stars: 8 / 50
 |        Mon        | Tue | Wed | Thu |        Fri        |        Sat        |        Sun        |
-|:-----------:|:---:|:---:|:---:|:-----------------:|:-----------------:|:-----------------:|
+|:-----------------:|:---:|:---:|:---:|:-----------------:|:-----------------:|:-----------------:|
 |                   |     |     |     | 1<br>:star::star: | 2<br>:star::star: | 3<br>:star::star: |
-| 4<br>:star: |  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/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/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)
+  }
+}