Adding day 3

day3/part1.scala

@@ -0,0 +1,33 @@
+import scala.io.StdIn.readLine
+
+case class Claim(id: Int, x: Int, y: Int, w: Int, h: Int) {
+  val xe: Int = x + (w - 1)
+  val ye: Int = y + (h - 1)
+
+  def getSquares: Seq[(Int, Int)] =
+    for {
+      xi <- x to xe
+      yi <- y to ye
+    } yield (xi, yi)
+}
+
+object Claim {
+  def apply(input: String): Claim =
+    "#(\\d+) @ (\\d+),(\\d+): (\\d+)x(\\d+)".r.findFirstMatchIn(input).map {
+      m => Claim(m.group(1).toInt, m.group(2).toInt, m.group(3).toInt, m.group(4).toInt, m.group(5).toInt)
+    }.get
+}
+
+val input = Iterator
+  .continually(readLine)
+  .takeWhile(_ != null)
+  .map(Claim.apply)
+
+val res = input
+  .flatMap(_.getSquares)
+  .foldLeft(Map.empty[(Int, Int), Int]) {
+    (acc, sq) => acc + (sq -> (acc.getOrElse(sq, 0) + 1))
+  }
+  .count(_._2 > 1)
+
+println(res)