Adding day 3

day3/part2.scala

@@ -0,0 +1,35 @@
+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), Int)] =
+    for {
+      xi <- x to xe
+      yi <- y to ye
+    } yield ((xi, yi) -> id)
+}
+
+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 claims = Iterator
+  .continually(readLine)
+  .takeWhile(_ != null)
+  .map(Claim.apply)
+  .toList
+
+val fabric = claims
+  .flatMap(_.getSquares)
+  .foldLeft(Map.empty[(Int, Int), Set[Int]]) {
+    (acc, sq) => acc + (sq._1 -> (acc.getOrElse(sq._1, Set.empty[Int]) + sq._2))
+  }
+
+val overlapping = fabric.filter(_._2.size > 1).values.flatten.toSet
+
+println(claims.filterNot(c => overlapping.contains(c.id)))