binary search

BinarySearch.kt

private fun binarySearch(list: List<Int>, key: Int, min: Int, max: Int): Int {
    if (max < min) {
        return -1
    }

    val mid = min + (max - min) / 2
    return when {
        list[mid] > key -> binarySearch(list, key, min, mid - 1)
        list[mid] < key -> binarySearch(list, key, mid + 1, max)
        else -> mid
    }
}