快速排序

public class test2 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		int[] a={3,2,5,7,9,1,3};
		quicksort(a,0,a.length-1);
		for (int i = 0; i < a.length; i++) {
			System.out.print(a[i]+" ");
		}
	}
	public static void quicksort(int[]arr,int low,int high) {
		
		if (low<high) {
			int a=getmiddle(arr, low, high);
			quicksort(arr, low, a-1);
			quicksort(arr, a+1, high);
		}
		
	}
	public static int getmiddle(int[] arr,int low,int high) {
		
		int temp=arr[low];
		while (low<high) {
			while (low<high &&arr[high]>=temp) {
					high--;
			}
			arr[low]=arr[high];
			while(low<high && arr[low]<=temp){
				low++;
			}
			arr[high]=arr[low];
			
		}
		arr[low]=temp;
		return low;
	}


}