package com.algorithm.sort;

import java.util.Arrays;

/**

* @author chen_wj

* @Description:

* @date 2019/11/19

* @Description: 快速排序

* @modifier

*/

public class QuickSort {

public static void main(String[] args) {

int[] arr = new int[]{4,10,9,8,7,6,5,4,3,1,2,1,8};

quickSort(arr,0,arr.length-1);

System.out.println(Arrays.toString(arr));

Arrays.sort(arr);

}

/**

* 快速排序

* @param arr

* @param start

* @param end

* @return

*/

public static int[] quickSort(int arr[],int start,int end) {

int pivot = arr[start];

int i = start;

int j = end;

while (i<j) {

while ((i<j)&&(arr[j]>pivot)) {

j--;

}

while ((i<j)&&(arr[i]<pivot)) {

i++;

}

if ((arr[i]==arr[j])&&(i<j)) {

i++;

} else {

int temp = arr[i];

arr[i] = arr[j];

arr[j] = temp;

}

}

if(i-1>start) {

arr=quickSort(arr,start,i-1);

}

if(j+1<end){

arr=quickSort(arr,j+1,end);

}

return arr;

}

}