object vezbe {
  def abs(x: Double): Double = if (x < 0) -x else x

  def sqrt(x: Double) = {
    def sqrtIter(guess: Double, x: Double): Double =
      if (isGoodEnough(guess, x)) guess
      else sqrtIter(improve(guess, x), x)

    def isGoodEnough(guess: Double, x: Double) =
      abs(guess * guess - x) < 1e-5

    def improve(guess: Double, x: Double) =
      (guess + x / guess) / 2
      
    sqrtIter(1, x)
  }

  def main(args: Array[String]): Unit = {
    println("Koren od 2 je " + sqrt(2))
  }
}