golang快速排序

package main
import "fmt"

func QuickSort(A []int, p, r int) {
	if p < r {
		q := Partition(A, p, r)
		QuickSort(A, p, q-1)
		QuickSort(A, q+1, r)
	}
}

func Partition(A []int, p, r int) int {
	x := A[p]
	i := p

	for j := p + 1; j <= r; j++ {
		if A[j] <= x {
			i++
			A[i], A[j] = A[j], A[i]
		}
	}

	A[p], A[i] = A[i], A[p]
	return i
}


func main() {
	A := []int{3, 6, 9, 9, 8, 4, 2, 1}
	fmt.Println(A)

	QuickSort(A, 0, len(A)-1)
	fmt.Println(A)
}