Quicksort Kotlin with while loop

fun rezaQuickSort(array: IntArray, left: Int, right: Int) {


        val pIndex = rezaPartiion(array, left, right)

        if(left < pIndex - 1) {
            rezaQuickSort(array, left, pIndex - 1)
        }
        if(pIndex < right) {
            rezaQuickSort(array, pIndex , right)
        }
    }

    fun rezaPartiion(array: IntArray, left: Int, right: Int ): Int {

        var pivot = array[(right+left)/2]

        var leftIndex = left
        var rightIndex = right

        while (leftIndex <= rightIndex) {

            while (array[leftIndex] < pivot) {
                    leftIndex++
            }

            while (array[rightIndex] > pivot) {
                rightIndex--
            }
            if(leftIndex <= rightIndex ) {
                rezaExchange(array, leftIndex, rightIndex)
                leftIndex++
                rightIndex--
            }
        }

       rezaExchange(array, leftIndex, right)

        return leftIndex

    }

    fun rezaExchange(array: IntArray, left: Int, right: Int) {
        val temp = array[left]
        array[left] = array[right]
        array[right] = temp
    }