快速排序

package QuickSort;

public class QuickSort {
    //时间复杂度O（nlogn） 最坏O（n2） 
    //空间复杂度O（logn) 最坏O（n)
    public static void main(String[] args){
        int[] a = {55,99,44,22,44,55,99,44,22,44,888,4};
        quicksort(a,0,a.length-1);
        for(int i=0;i<a.length;i++){
                System.out.print(a[i]+" ");
        }
    }
    
    public static void quicksort(int[] a,int low, int high){
        if(low<high){//不加这个下面分段就越界了
            int middle=getmiddle(a,low,high);
            quicksort(a,middle+1,high);
            quicksort(a,0,middle-1);
        }
    }
    
    public static int getmiddle(int[] a ,int low, int high){
        int temp =a[low];
        while(low<high){
            while(low<high&&temp<=a[high]){
                high--;
            }
            a[low]=a[high];
            while(low<high&&a[low]<=temp){
                low++;
            }
            a[high]=a[low];
        }
        a[low]=temp;
        return low;
    }
}