#14, solution2.1.7.3_SW.scala added

Signed-off-by: Andreas Roehler <[email protected]>

chapter02/worksheets/solution2.1.7.3_SW.scala

@@ -0,0 +1,13 @@
+/** author: Sergei Winitzki */
+
+/** Exercise 2.1.7.3
+Given two sequences p: Seq[String] and q: Seq[Boolean] of equal length, compute a
+Seq[String] with those elements of p for which the corresponding element of q is true.
+Hint: use zip, map, filter. */ 
+
+val names: List[String]        = List("Joe", "Bob", "Mary")
+val a: List[Boolean]           = List(true, false, true)
+val b: List[(String, Boolean)] = names.zip(a)
+val c: List[(String, Boolean)] = b.filter { case (x, y) => y }
+val d: List[String]            = c.map { case (x, y) => x }
+