Some problem inspired by fsarradin, from https://groups.google.com/forum/?hl=fr&fromgroups=#!topic/paris-scala-user-group/7dqP4ubUyDY (https://groups.google.com/forum/?hl=fr&fromgroups=#%21topic/paris-scala-user-group/7dqP4ubUyDY)

gistfile1.scala

/**
 Robin est le genre de personne à avoir plusieurs comptes dans plusieurs banques.
 Elle s'est créée un petit programme en Scala pour pouvoir récupérer le solde de ses comptes auprès
 des différentes banques, à partir de son propriétaire.
 */

case class Account(id: String, bankName: String, owner: String, amount: Int)

object AccountRepository extends App {

  val banks: Map[String, Set[Account]] =
    Map(
      "GNB" -> Set(Account("CC1", "GNB", "Robin", 5000), Account("CC2", "GNB", "Barney", 9015000)),
      "La Boob Postale" -> Set(Account("CP1", "La Boob Postale", "Robin", 2000)),
      "Tortue Genaiale" -> Set(Account("TGN1", "Tortue Genaiale", "Ted", 150)),
      "Credit Rural" -> Set(Account("CRL1", "Credit Rural", "Lily & Marshall", 50000))
    )

  def findAccountsByOwner(owner: String): List[(String, Int)] = {
    val ownerAccounts: List[Account] = banks.flatMap(b => b._2.filter(_.owner == owner)).toList
    ownerAccounts.map(acc => (acc.bankName, acc.amount))
  }

  println(findAccountsByOwner("Robin")) // List((GNB,5000), (La Boob Postale,2000))
  println(findAccountsByOwner("Barney")) // List((GNB,9015000))
  println(findAccountsByOwner("Tondeuse")) //) List()
}