day 7 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: 13 / 50
+#### Stars: 14 / 50
 |        Mon        |        Tue        |        Wed        |        Thu        |        Fri        |        Sat        |        Sun        |
-|:-----------------:|:-----------------:|:-----------------:|:-----------:|:-----------------:|:-----------------:|:-----------------:|
+|:-----------------:|:-----------------:|:-----------------:|:-----------------:|:-----------------:|:-----------------:|:-----------------:|
 |                   |                   |                   |                   | 1<br>:star::star: | 2<br>:star::star: | 3<br>:star::star: |
-| 4<br>:star::star: | 5<br>:star::star: | 6<br>:star::star: | 7<br>:star: |         8         |         9         |        10         |
+| 4<br>:star::star: | 5<br>:star::star: | 6<br>:star::star: | 7<br>:star::star: |         8         |         9         |        10         |
 |        11         |        12         |        13         |        14         |        15         |        16         |        17         |
 |        18         |        19         |        20         |        21         |        22         |        23         |        24         |
 |        25         |                   |                   |                   |                   |                   |                   |

src/day7/Hand2.scala

@@ -0,0 +1,65 @@
+package day7
+
+import scala.collection.mutable
+
+class Hand2(var cards: Array[Int], val bid: Int) {
+
+  def getType(): Int = {
+    val cardsMap: mutable.Map[Int, Int] = new mutable.HashMap()
+    val jokers: Int = cards.count(c => c == 0)
+    for (card: Int <- cards) {
+      if (card != 0) {
+        if (!cardsMap.contains(card)) {
+          cardsMap(card) = 0
+        }
+        cardsMap(card) += 1
+      }
+    }
+
+    val keys: Array[Int] = cardsMap.keys.toArray
+    val values: Array[Int] = cardsMap.values.toArray
+
+    if (jokers == 5) return 6
+
+    // Five of a kind
+    for (value: Int <- values) {
+      if (value + jokers == 5) return 6
+    }
+
+    // Four of a kind
+    for (value: Int <- values) {
+      if (value + jokers == 4) return 5
+    }
+
+    // Full house
+    val sortedValues: Array[Int] = values.sorted(Ordering.Int.reverse)
+    if (sortedValues(0) + sortedValues(1) + jokers >= 5) return 4
+
+    // Three of a kind
+    if (sortedValues(0) + jokers >= 3) return 3
+
+    // Two pairs
+    if (sortedValues(0) + sortedValues(1) + jokers >= 4) return 2
+
+    // One pair
+    if (sortedValues(0) + jokers >= 2) return 1
+
+    return 0
+  }
+
+  def isBetter(hand: Hand2): Boolean = {
+    val t1: Int = getType()
+    val t2: Int = hand.getType()
+    if (t1 > t2) return true
+    if (t1 < t2) return false
+
+    for ((c1: Int, c2: Int) <- cards.zip(hand.cards)) {
+      if (c1 != c2) {
+        return c1 > c2
+      }
+    }
+    return false
+  }
+
+  override def toString: String = s"Hand(${cards.mkString}, $bid, ${getType()})"
+}

src/day7/Puzzle2.scala

@@ -0,0 +1,46 @@
+package day7
+
+import scala.io.{BufferedSource, Source}
+
+object Puzzle2 {
+  val CARDS: Array[Int] = Array('J', '2', '3', '4', '5', '6', '7', '8', '9', 'T', 'Q', 'K', 'A')
+  var hands: Array[Hand2] = Array.empty
+
+  def loadInput(path: String): Unit = {
+    val source: BufferedSource = Source.fromFile(path)
+    val lines: Array[String] = source.getLines().toArray
+
+    hands = new Array(lines.length)
+
+    for ((line: String, i: Int) <- lines.zipWithIndex) {
+      val parts: Array[String] = line.split(" ")
+      val cards: Array[Int] = parts(0).map(c => CARDS.indexOf(c)).toArray
+      val bid: Int = parts(1).toInt
+      hands(i) = new Hand2(cards, bid)
+    }
+
+    source.close()
+  }
+
+  def sortHands(): Unit = {
+    hands = hands.sortWith((h1: Hand2, h2: Hand2) => h2.isBetter(h1))
+  }
+
+  def solve(path: String): Int = {
+    loadInput(path)
+    sortHands()
+
+    var solution: Int = 0
+
+    for ((hand: Hand2, i: Int) <- hands.zipWithIndex) {
+      solution += hand.bid * (i+1)
+    }
+
+    return solution
+  }
+
+  def main(args: Array[String]): Unit = {
+    val solution: Int = solve("./res/day7/input1.txt")
+    println(solution)
+  }
+}

tests/day7/Puzzle2Test.scala

@@ -0,0 +1,9 @@
+package day7
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class Puzzle2Test extends AnyFunSuite {
+  test("Puzzle2.solve") {
+    assert(Puzzle2.solve("tests_res/day7/input1.txt") == 5905)
+  }
+}