fun binarySearch(array: List<Int>, number: Int): Int {
  var left = 0
  var right = array.count() - 1

  while (left < right) {
    val middle = (left + right) / 2

    if (number < array[middle]) {
      right = middle
    } else if (number > array[middle]) {
      left = middle + 1
    } else {
      return middle
    }
  }

  if (left < array.count() && array[left] == number) {
    return left
  }

  return -1
}

fun main() {
  val array = listOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
  val number = 8

  val index = binarySearch(array, number)

  if (index == -1) {
    println("Szukanej liczby nie ma na liscie")
  } else {
    println("Szukana liczba znajduje sie pod indeksem $index")
  }
}