java 快速排序

package com.company.sort;

/*
练习快速排序
纯属练手感
 */

public class reviewQuickSort {
    public static int[] sort(int[] arr, int start, int end){
        if(start < end){
            //基本数值
            int baseNum = arr[start];
            //中间值
            int middleNum;
            int i = start;
            int j = end;

            do{
                while ((arr[i] < baseNum) && i < end){
                    i++;
                }
                while((arr[j] > baseNum) && j > start){
                    j--;
                }
                if(i<=j){
                    middleNum = arr[i];
                    arr[i] = arr[j];
                    arr[j] = middleNum;
                    i++;
                    j--;
                }

            }while(i<=j);
            if(start < j){
                sort(arr, start, j);
            }

            if(end > i){
                sort(arr, i, end);
            }


        }

        return arr;
    }

}