对于一个int数组，请编写一个快速排序算法，对数组元素排序。
给定一个int数组A及数组的大小n，请返回排序后的数组。

测试样例：

[1,2,3,5,2,3],6
[1,2,2,3,3,5]
我的提交

-- coding:utf-8 --

class QuickSort:
def quickSort(self, A, n):

write code here

    self.quick(A, 0, n - 1)
    return A

def quick(self, A, left, right):
    if left >= right:
        return
    t = A[left]
    l = left
    r = right

    while l < r:
        while t <= A[r] and l < r:
            r -= 1
        if l < r:
            A[l] = A[r]
            l += 1

        while t >= A[l] and l < r:
            l += 1
        if l < r:
            A[r] = A[l]
            r -= 1

    # if l > r:
    A[l] = t
    if left < r-1:
        self.quick(A, left, r-1)
    if r + 1 < right:
        self.quick(A, r + 1, right)
    return

参考答案
python版本1

-- coding:utf-8 --

class QuickSort:
def quickSort(self, A, n):

write code here

    return self.quick_sort(A)

def quick_sort(self, seq):
    # 快排: 取一个基准数,自己意愿取最左
    # 
    if seq == []:
        return []
    else:
        pivot = seq[0]
        lesser = self.quick_sort([x for x in seq[1:] if x < pivot])
        greater = self.quick_sort([y for y in seq[1:] if y >= pivot])
        return lesser+[pivot]+greater

python版本2

-- coding:utf-8 --

class QuickSort:
def func(self,a,left, right):
if left>=right:
return
j = left-1
i = left
while i<=right:
if a[i]<=a[right]:
j = j+1
a[j],a[i]=a[i],a[j]
i += 1
self.func(a,left,j-1)
self.func(a,j+1,right)
def quickSort(self, A, n):
left = 0
right = n-1
self.func(A,left,right)
return A

write code here

python 版本2

-- coding:utf-8 --

class QuickSort:
def quickSort(self, A, n):

write code here

    self.quick(A, 0, n - 1)
    return A

def quick(self, A, left, right):
    if left >= right:
        return
    t = A[left]
    l = left    # 这里不能为 l = left + 1
    r = right

    while l < r:
        while t <= A[r] and l < r:
            r -= 1
        while t >= A[l] and l < r:
            l += 1

        if l < r:
            A[l], A[r] = A[r],A[l]

    A[left], A[r] = A[r],A[left]
    if left < r-1:
        self.quick(A, left, r-1)
    if r + 1 < right:
        self.quick(A, r + 1, right)
    return

if name == 'main':
q = QuickSort()
print(q.quickSort([8,12,14,17,26,27,28,35,36,44,44,48,54],6))
java版本
public class QuickSort {

public static void quickSort(int[] arr) {
    if (arr == null || arr.length < 2) {
        return;
    }
    process(arr, 0, arr.length - 1);
}

public static void process(int[] arr, int left, int right) {
    if (left < right) {
        int random = left + (int) (Math.random() * (right - left + 1));
        swap(arr, random, right);
        int mid = partition(arr, left, right);
        process(arr, left, mid - 1);
        process(arr, mid + 1, right);
    }
}

public static int partition(int[] arr, int left, int right) {
    int pivot = left - 1;
    int index = left;
    while (index <= right) {
        if (arr[index] <= arr[right]) {
            swap(arr, ++pivot, index);
        }
        index++;
    }
    return pivot;
}

public static void swap(int[] arr, int index1, int index2) {
    int tmp = arr[index1];
    arr[index1] = arr[index2];
    arr[index2] = tmp;
}

public static int[] generateArray(int len, int range) {
    if (len < 1) {
        return null;
    }
    int[] arr = new int[len];
    for (int i = 0; i < len; i++) {
        arr[i] = (int) (Math.random() * range);
    }
    return arr;
}

public static void printArray(int[] arr) {
    if (arr == null || arr.length == 0) {
        return;
    }
    for (int i = 0; i < arr.length; i++) {
        System.out.print(arr[i] + " ");
    }
    System.out.println();
}

public static boolean isSorted(int[] arr) {
    if (arr == null || arr.length < 2) {
        return true;
    }
    for (int i = 1; i < arr.length; i++) {
        if (arr[i - 1] > arr[i]) {
            return false;
        }
    }
    return true;
}

public static void main(String[] args) {
    int len = 10;
    int range = 10;
    int testTimes = 50000;
    for (int i = 0; i < testTimes; i++) {
        int[] arr = generateArray(len, range);
        quickSort(arr);
        if (!isSorted(arr)) {
            System.out.println("Wrong Case:");
            printArray(arr);
            break;
        }
    }

    int len2 = 13;
    int range2 = 10;
    int testTimes2 = 50000;
    for (int i = 0; i < testTimes2; i++) {
        int[] arr = generateArray(len2, range2);
        quickSort(arr);
        if (!isSorted(arr)) {
            System.out.println("Wrong Case:");
            printArray(arr);
            break;
        }
    }
}

}