// Solution #1
fun deleteNth1(elements: IntArray, maxOccurrences: Int) : IntArray {
    //  LinkedHashMap preserves the entry iteration order.
    val occurrencesMap = LinkedHashMap<Int, Int>()
    elements.forEach { element ->
        occurrencesMap[element] = (occurrencesMap[element] ?: 0) + 1
    }
    return occurrencesMap.map { entry ->
        val occurrences = if (entry.value < maxOccurrences) entry.value else maxOccurrences
        Array(occurrences) { entry.key }
    }.toTypedArray().flatten().toIntArray()
}

// Solution #2
fun deleteNth2(elements: IntArray, maxOccurrences: Int) : IntArray {
    return elements.groupBy { it }
        .flatMap { group -> group.value.take(maxOccurrences) }
        .toIntArray()
}

// Solution #3
fun deleteNth3(elements: IntArray, maxOccurrences: Int) : IntArray {
    val occurrencesMap = LinkedHashMap<Int, Int>()

    // array can be larger
    val array = Array(elements.size) { 0 }

    var index = 0
    for (element in elements) {
        val occurrences = occurrencesMap[element] ?: 0
        val newOccurrences = occurrences + 1

        if (newOccurrences <= maxOccurrences) {
            array[index] = element
        }

        occurrencesMap[element] = newOccurrences
    }
    
    return array.toIntArray()
}