day 7 puzzle 1

src/day7/Hand.scala

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+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

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+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)
+  }
+}