HTW Berlin Web Technology Scala Balanced improved -ESS

object Balanced {
  def main(args: Array[String]) {
    val s1: String = "((a))"
    val s2: String = "a - )())()x("
    println(balanced(s1.toList))
    println(balanced(s2.toList))
}
   def balanced (s: List[Char]): Boolean ={
     def countChar(l: List[Char], count: Int, s: Char): Int = {
      if (l.isEmpty) count
      else {
        if (s == l.head) countChar(l.tail, count + 1, s)
        else countChar(l.tail, count, s)
      }
    }
    def check (s: List[Char], c: Int): Boolean= {
      if (s.isEmpty && c == 0) true
      else if( s.isEmpty && c != 0) false
      else if(s.head == '(') check(s.tail, c +1)
      else if (s.head == ')' && c >0) check(s.tail, c -1)
      else check(s.tail, c)
    }
    if (countChar(s, 0, '(') == countChar(s, 0, ')'))  check(s, 0)
   else false

  }
}