Sort the Quick sort

package com.xsz.demo;/**    *  @author  cwqi   *  @date  2015-1-6   *///sort of the quick sort, the basic idea for the division + digging pits, there are two ways: one is double-sided scan, and the other is a single scan. public class quicksort {public static void main  (String[] args) {int  a[] ={2,3,30,1,4,56,2,7,3,8};//int a[] ={4,5,6,2,7,3,8};//int a[] ={1,5,4,3,8 };//int a[] ={1,1};//int a[] ={1};//int a[] ={};//int a[] =null;int  start=0;int end= a==null? -1:a.length -1;//singlescan (a,start,end);d Oublescan (A, Start,end);p rint (a,end);} Static void doublescan (int[] a, int start, int end)  { if (start  < end) {          int i = start,  j = end, key = a[start];           while (i < j) {          //from behind, looking for elements smaller than key values              while ( i < j && a[j] >=  Key) {                   j--;              }               if (I&NBSP;&LT;&NBSP;J) {                   a[i++] =  a[j];              }                            //from the front looking for elements larger than the key value              while (i &Lt; j && a[i] <= key) {                   i++;               }               if (I&NBSP;&LT;&NBSP;J) {                   a[j--] = a[i];               }          }                   a[i]  = key;  //i is the center of         doublescan (A, start, &NBSP;I-1);           doublescan (a, i+1, end);      &nbSP;}    }static void singlescan (int[] a, int s, int e)  {int  j = s+1;//int p = s;//Sub-location if  (s < e)  {int key  =a[s];//key value while  (j<=e) {if (A[j] <= key) {p++ ;//system.out.println ("key->" + key); Int temp =a[p];a[p] = a[j];a[j]=temp;//system.out.println ("Exchange----->" +a[j]+ " " +a[p]); j++ ;} else {j++ ;}} Place the key value in the sub-location Int temp =a[s];a[s] = a[p];a[p]=temp;singlescan (a, s, p-1); Singlescan (a, p+1, e);}} Static void print (int[]array ,int l) {for  (int i = 0; i <=  l; i++)  {system.out.print (array[i]+ " ");}}

Sort the Quick sort