大的放指标右边，小的放指标左边：交换左右指针

import java.util.Arrays;

public class QuickSort {
    public static void main(String[] args) {
        int[] arr = new int[]{6, 1, 2, 7, 9, 3, 4, 5, 10, 8};
        quickSort(arr,0,arr.length-1);
        System.out.println(Arrays.toString(arr));
    }


    public static void quickSort(int[] arr,int left,int right){
        if (left >= right){
            return;//用于递归
        }
        int base = arr[left];
        int i = left;
        int j = right;

        while (i != j){
            while (arr[j] >=base && i<j){
                j--;//右指针大，就让右指针往左走
            }
            while (arr[i] <= base && i<j){
                i++;//左指针大，就让左指针往右走
            }
            //如果左指针不大，右指针不小，就交换两个指针的位置
            int temp = arr[i];
            arr[i] = arr[j];
            arr[j] = temp;
        }
        arr[left] = arr[i];
        arr[i] = base;

        quickSort(arr,left,i-1);
        quickSort(arr,i+1,right);
    }

}