QuickSort.kt

// ============== Quick sort  start  20151015==============

fun quickSort(a: IntArray, lowOffset: Int, highOffset: Int) {

    if (lowOffset > highOffset ) return;

    // find pivot
    var pivot: Int = a[highOffset]
    var nextSmallTail = lowOffset;

    // partition
    for ( i in lowOffset..highOffset-1){
        if ( a[i] <= pivot ){
            swap(a,i,nextSmallTail)
            nextSmallTail++
        }
    }

    swap(a,nextSmallTail,highOffset)
    pivot = nextSmallTail

    quickSort(a,lowOffset, pivot-1)
    quickSort(a,pivot+1,highOffset)

}
// ============== Quick sort  end  20151015==============


fun main(args: Array<String>) {
    var array = intArrayOf( 6,5,4,3,2,1)
    array.forEach { i -> print(i) }
    println("")
    quickSort(array,0,array.size()-1)
    array.forEach { i -> print(i) }

}