快速排序Java代码

/*讲解网址

http://wenku.baidu.com/link?url=1xofQsF1043cyk06D7L_OWOJUna67Lx3GNK9Qg6HbADlRH_TMnLx-3EVVlrTVUVqa9c442X576VsAlq8YTp8v7O9P7c_VTiBM7gD_08wYe3

*/

package quickSort;



/**

 * 快速排序

 * @author Administrator

 *

 */

public class QuickSort {

    void swap(int[] a,int i,int j){

        int temp;

        temp=a[i];

        a[i]=a[j];

        a[j]=temp;

    }

    

    int pos(int[] a,int low,int high){

        int temp=a[low],i=low,j=high;

        while(i<j){

            while(i<j){

                while((a[j]>=temp)&&(i<j)){

                    j--;

                }

                if(i<j){

                    swap(a,i,j);

                    i++;

                }

                while((a[i]<=temp)&&(i<j)){

                    i++;

                }

                if(i<j){

                    swap(a,i,j);

                    j--;

                }

            }

        }

        return i;

    }

    

    void quickSort(int[] a,int low,int high){

        int pos;

        if(low<high){

            pos=pos(a,low,high);

            quickSort(a,low,pos-1);

            quickSort(a,pos+1,high);

        }

    }



}





package quickSort;



/**

 * 测试类

 * @author Administrator

 *

 */

public class Test {

    public static void main(String[] args){

        final int N=(int)(Math.random()*100+1);

        QuickSort q=new QuickSort();

        int[] a=new int[N];

        

        for(int j=0;j<N;j++){

            a[j]=(int)(Math.random()*100);

        }

        

        System.out.println("排序前：");

        for(int i=0;i<a.length;i++){

            System.out.print(a[i]+" ");

        }

        

        q.quickSort(a,0,a.length-1);

        System.out.println("排序后：");

        for(int i=0;i<a.length;i++){

            System.out.print(a[i]+" ");

        }

    }



}