 Solution

class IntegerSetWithCount extends IntegerSetPattern() {
  private val delegate = new IntegerSet()
  private var attempts = BigInt(0)

  override def contains(x: Int): Boolean = delegate.contains(x)

  override def insert(x: Int): Unit = {
    attempts += 1
    val wasPresent = delegate.contains(x)
    delegate.insert(x)
    if (!wasPresent) size += 1
  }
  override def delete(x: Int): Unit = {
    val wasPresent = delegate.contains(x)
    delegate.delete(x)
    if (wasPresent) size -= 1
  }
  override def pop(): Int = {
    if (isEmpty) throw new NoSuchElementException("set is empty")
    val answer = delegate.pop()
    size -= 1
    answer
  }
  override def clear: Unit = {
    delegate.clear
    size = 0
    attempts = BigInt(0)
  }
  def getCount: BigInt = attempts
}