added assignment 6 ex 3

src/Assignment6/Ex3.sc

@@ -0,0 +1,22 @@
+val cities = List("Paris", "London", "Berlin", "Lausanne")
+val relatives = List("Grandma", "Grandpa", "Aunt Lottie", "Dad")
+val travellers = List("Pierre-Andre", "Rachel")
+
+def generatePostcards(cities: List[String], relatives: List[String], travellers: List[String]): List[String] = {
+  for (t <- travellers;
+       r <- relatives;
+       c <- cities) yield s"Dear $r, Wish you were here in $c! Love, $t"
+}
+
+def generatePostcards2(cities: List[String], relatives: List[String], travellers: List[String]): List[String] = {
+  for (t <- travellers;
+       r <- relatives;
+       c <- cities;
+       if r.startsWith("G")) yield s"Dear $r, Wish you were here in $c! Love, $t"
+}
+
+val cards: List[String] = generatePostcards(cities, relatives, travellers)
+println(cards.mkString("\n"))
+
+val cards2: List[String] = generatePostcards2(cities, relatives, travellers)
+println(cards2.mkString("\n"))