Add alternative solution for orderDec

src/main/scala/concpar22final03/Problem3.scala

@@ -30,6 +30,23 @@ trait Problem3:
       soldCards.flatMap { _ => buyListOfCards(wantedDeck) }
     }.flatten
 
+  /** Alternative implementation of orderDeck.
+    */
+  def orderDecAlt(
+      bag: MoneyBag,
+      cardsToSell: List[Card],
+      wantedDeck: List[String]
+  ): Future[List[Card]] =
+    val totalGivenMoney =
+      cardsToSell.map(c => valueOf(c.name)).sum + moneyIn(bag)
+    val totalNeededMoney = wantedDeck.map(valueOf).sum
+    if totalGivenMoney < totalNeededMoney then
+      return Future.failed(new NotEnoughMoneyException())
+    val soldCards: Future[Any] =
+      if moneyIn(bag) != 0 then sellListOfCards(cardsToSell).zip(deposit(bag))
+      else sellListOfCards(cardsToSell)
+    soldCards.flatMap { _ => buyListOfCards(wantedDeck) }
+
   /** This helper function will sell the provided list of cards and put the
     * money on your personal bank account. It returns a Future of Unit, which
     * indicates when all sales are completed.