func QuickSort(arr *array.List, left int, right int, fn SelectPivot) {
if (right - left) <= 0 {
return
}
pvt := fn(left, right)
if pvt != right {
arr.Swap(pvt, right)
}
divider := Partition(arr, left, right)
QuickSort(arr, left, divider-1, fn)
QuickSort(arr, divider+1, right, fn)
}
func Partition(arr *array.List, left, right int) int {
i := left - 1
j := i + 1
for j < right {
if ret, _ := arr.Compare(j, right); ret < 0 {
i += 1
arr.Swap(i, j)
j += 1
} else {
j += 1
}
}
arr.Swap(right, i+1)
return i + 1
}