在数据规模不是很大的情况下效率很高，一个简单又经典的算法。

理解了思想不论用什么语言实现起来都是很容易的，下面是用 golang 描述的快速排序算法

package main

import (
	"fmt"
)

func main() {
	var num = []int{3, 2, 4, 6, 5, 1}
	num = IntQSort(num, true)
	fmt.Println(num)
}

func IntQSort(n []int, order bool) []int {
	ls := make([]int, len(n))
	for i := range n {
		ls[i] = n[i]
	}
	return IntQuickSort(ls, order)
}

/*  快速排序算法
*	ls 排序码数组
*	order true 表示升序，false 表示降序
 */
func IntQuickSort(ls []int, order bool) []int {
	tmp := ls[0]
	left, i := 0, 0
	right, j := len(ls)-1, len(ls)-1
	d := 1
	if left < right {
		for i < j {
			if order == true {
				if d == 1 {
					if tmp > ls[j] {
						ls[i] = ls[j]
						i += 1
						d = -1
					} else {
						j -= 1
						d = 1
					}
				} else {
					if tmp < ls[i] {
						ls[j] = ls[i]
						j -= 1
						d = 1
					} else {
						i += 1
						d = -1
					}
				}
				if i == j {
					ls[i] = tmp
				}
			} else {
				if d == 1 {
					if tmp < ls[j] {
						ls[i] = ls[j]
						i += 1
						d = -1
					} else {
						j -= 1
						d = 1
					}
				} else {
					if tmp > ls[i] {
						ls[j] = ls[i]
						j -= 1
						d = 1
					} else {
						i += 1
						d = -1
					}
				}
				if i == j {
					ls[i] = tmp
				}
			}
		}
		if i == right {
			IntQuickSort(ls[left:i], order)
		} else if i == 0 {
			IntQuickSort(ls[i+1:right+1], order)
		} else {
			IntQuickSort(ls[left:i], order)
			IntQuickSort(ls[i+1:right+1], order)
		}
	}
	return ls
}