import scala.collection.mutable.ListBuffer

object Max {

  // tail recursive calculation
  def maxTail(list: List[Int]): Int = {

    // local function
    def maxTailLocal(list: List[Int], max: Int): Int = {

      if (list.isEmpty) {
        max
      } else if (list.head > max)
        maxTailLocal(list.tail, list.head)
      else {
        maxTailLocal(list.tail, max)
      }
    }

    //local function call
    maxTailLocal(list, Int.MinValue)
  }

  // pattern matching calculation
  def maxPattern(list: List[Int]): Int = {

    //local function
    def maxPatternLocal(list: List[Int], max: Int): Int = list match {
      case List() => max
      case head :: tail => if (head > max)
        maxPatternLocal(tail, head)
      else
        maxPatternLocal(tail, max)
    }

    //local function call
    maxPatternLocal(list, Int.MinValue)
  }


  def main(args: Array[String]) {

    if(args.length < 1){
      Console.err.println("You have to pass a list of integer arguments!")
      return
    }

    val listBuffer = new ListBuffer[Int]

    print("List: ")
    for (arg <- args) {
      listBuffer += arg.toInt
      print(arg + " ")
    }
    println()

    println("Max value tail recursion: " + maxTail(listBuffer.toList))
    println("Max value pattern matching: " + maxPattern(listBuffer.toList))

  }
}