day 7 puzzle 1

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: 12 / 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  |         8         |         9         |        10         |
-|        11         |        12         |        13         | 14  |        15         |        16         |        17         |
-|        18         |        19         |        20         | 21  |        22         |        23         |        24         |
-|        25         |                   |                   |     |                   |                   |                   |
+#### Stars: 13 / 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         |
+|        11         |        12         |        13         |     14      |        15         |        16         |        17         |
+|        18         |        19         |        20         |     21      |        22         |        23         |        24         |
+|        25         |                   |                   |             |                   |                   |                   |

src/day7/Hand.scala

@@ -0,0 +1,47 @@
+package day7
+
+import scala.collection.mutable
+
+class Hand(var cards: Array[Int], val bid: Int) {
+  def getType(): Int = {
+    val cardsMap: mutable.Map[Int, Int] = new mutable.HashMap()
+    for (card: Int <- cards) {
+      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 (keys.length == 1) {
+      return 6
+    }
+    if (keys.length == 2) {
+      if (values.contains(4)) return 5
+      if (values.contains(3) && values.contains(2)) return 4
+    }
+    if (values.contains(3)) return 3
+    if (values.contains(2)) {
+      if (values.count(v => v == 2) == 2) return 2
+      return 1
+    }
+    return 0
+  }
+
+  def isBetter(hand: Hand): 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/Puzzle1.scala

@@ -0,0 +1,46 @@
+package day7
+
+import scala.io.{BufferedSource, Source}
+
+object Puzzle1 {
+  val CARDS: Array[Int] = Array('2', '3', '4', '5', '6', '7', '8', '9', 'T', 'J', 'Q', 'K', 'A')
+  var hands: Array[Hand] = 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 Hand(cards, bid)
+    }
+
+    source.close()
+  }
+
+  def sortHands(): Unit = {
+    hands = hands.sortWith((h1: Hand, h2: Hand) => h2.isBetter(h1))
+  }
+
+  def solve(path: String): Int = {
+    loadInput(path)
+    sortHands()
+
+    var solution: Int = 0
+
+    for ((hand: Hand, 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/Puzzle1Test.scala

@@ -0,0 +1,9 @@
+package day7
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class Puzzle1Test extends AnyFunSuite {
+  test("Puzzle1.solve") {
+    assert(Puzzle1.solve("tests_res/day7/input1.txt") == 6440)
+  }
+}

tests_res/day7/input1.txt

@@ -0,0 +1,5 @@
+32T3K 765
+T55J5 684
+KK677 28
+KTJJT 220
+QQQJA 483