Floors.scala

/**
  * Created by jjst on 21/03/16.
  */
object Floors {

  def main(args: Array[String]): Unit = {
    Console.println(floorNumber1("())"))
    Console.println(floorNumber2("())"))
    Console.println(floorNumber2(""))
  }

  def floorNumber1(str: String): Int = floorNumber1(str.toList)

  def floorNumber1(str: List[Char]): Int = str match {
    case firstParens :: rest => firstParens match {
      case '(' => 1 + floorNumber1(rest)
      case ')' => -1 + floorNumber1(rest)
    }
    case Nil => 0
  }

  def floorNumber2(str: String): Int = floorNumber2(str.toList)

  def floorNumber2(str: List[Char]): Int = {
    str.map { char: Char => char match {
        case '(' => 1
        case ')' => -1
      }
    }.sum
  }

  def floorNumber3(str: List[Char]): Int = {
    str.foldLeft(0) { (i: Int, c: Char) =>
      val j = if(c == '(') 1 else -1
      i + j
    }
  }

}