merge sort

MergeSort.kt

// ============== merge sort start ==============
var numbers: IntArray = intArrayOf()
var temp: IntArray = intArrayOf()

fun merge(low: Int, middle: Int, high: Int) {

    for (i in low..high) {
        temp[i] = numbers[i];
    }
    var i = low;
    var j = middle + 1;
    var k = low;
    while (i <= middle && j <= high) {
        if (temp[i] <= temp[j]) {
            numbers[k] = temp[i];
            i++;
        } else {
            numbers[k] = temp[j];
            j++;
        }
        k++;
    }
    while (i <= middle) {
        numbers[k] = temp[i];
        k++;
        i++;
    }

}

fun mergesortImpl(low: Int, high: Int) {
    if (low < high) {
        var mid: Int = low + (high - low) / 2;
        mergesortImpl(low, mid);
        mergesortImpl(mid + 1, high);
        merge(low, mid, high);
    }
}

fun mergetSort(a: IntArray) {

    numbers = a;
    temp = a.copyOf();
    mergesortImpl(0, a.size() - 1);

}
// ============== merge sort  end  ==============

fun main(args: Array<String>) {
    val array = intArrayOf(7, 6, 5, 4, 3, 2, 1)
    array.forEach { i -> println(i) }
    mergetSort(array)
    array.forEach { i -> println(i) }
}