func qsort(arr []int, left int, right int) {
if left < right {
mid := partition(arr, left, right)
qsort(arr, left, mid-1)
qsort(arr, mid+1, right)
}
}
//寻找中元 注意是left <= right(而不是left<right) 因为如果有等于中元的key的元素,会死循环
func partition(arr []int, left int, right int) int {
key := arr[left]
for left < right {
for arr[right] > key && left <= right {
right--
}
if left < right {
arr[left], arr[right] = arr[right], arr[left]
left++
}
for arr[left] < key && left <= right {
left++
}
if left < right {
arr[left], arr[right] = arr[right], arr[left]
right--
}
}
arr[left] = key
return left
}
func main() {
arr := []int{10, 5, 6, 19, 35, 24, 17, 5}
qsort(arr, 0, len(arr)-1)
fmt.Println(arr)
}