Scala lab2

object Main1 {
  def isNegative(x: Int): Boolean = x < 0
  def sumNegative(lst: List[Int]): Int = {
    val negativeList = lst.filter(isNegative)
    if(negativeList.isEmpty) 0
    else {
      val result = negativeList.foldLeft(0)((ac_c, x) => ac_c + x)
      result
    }
  }
  def findTriplicate(lst: List[Int]): Option[Int] = {
  lst.find(x => lst.count(_ == x) == 3)
  }
  def main(args: Array[String]): Unit = {
    val myList = List(1, -1, -3, 2, 4, 1, 1, 5, 7, 9)
    println(myList.mkString(", "))
    val sum = sumNegative(myList)
    val tripple = findTriplicate(myList)
    println(s"1.Sum of negative numbers: $sum")
    println(s"5.Number that appears in list 3 times: $tripple")
  }
}