任意长度快排

快排定义：

             借鉴wiki对之的定义：http://en.wikipedia.org/wiki/Quicksort

 

代码实现：

 1 public class Quicsort {

 2     

 3     

 4     public void _quickSort(Integer[] list, int low, int high) {

 5         if (low < high) {

 6             int middle = getMiddle(list, low, high);  

 7             _quickSort(list, low, middle - 1);        //递归调用

 8             _quickSort(list, middle + 1, high);       

 9         }

10         //System.out.println(low);

11         

12     }

13 

14     public void quick(Integer[] str) {

15         if (str.length > 0) {   

16             _quickSort(str, 0, str.length - 1);

17         }

18     }

19     

20     private int getMiddle(Integer[] src, int start, int end) {

21         int tmp = src[start];

22         while (start < end) {

23             while (start < end && src[end] >= tmp) {

24                 end--;

25             }

26             src[start] = src[end];

27             while (start < end && src[start] <= tmp) {

28                 start++;

29             }

30             src[end] = src[start];

31         }   

32         src[start] = tmp; //一次排序

33         return start;     //返回小于tmp的个数即实现分割

34     }

35 

36 

37 }

import java.util.*; 

public class Test{  

      

   

      public static void main(String[] args) {  

          Scanner br=new Scanner(System.in);

          String f; 

          f=br.nextLine();     //把输入的字符串赋给f

          br.close();

          String  k[];

          k=f.split(" ");      //把f通过空格分割成字符串数组赋给字符串数组k

         

          ArrayList<Integer> y = new ArrayList<Integer>(); 

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

              String m=k[i];

              y.add(Integer.parseInt(m));

              // System.out.println(y.get(i)); 用于测试是否分割成功

              

          }

          Integer [] list ;

          list=(Integer[])y.toArray(new Integer[1]);  //把ArryList转换成Integer数组

          Quicsort qs=new Quicsort();  

             qs.quick(list);  

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

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

              }  

               System.out.println();  



        }  

  

}