关于快速排序的Java代码实现

 1 package test1;
 2 
 3 public class QuicSort {
 4     /*
 5      * 使用快速排序
 6      * arras:要排序的数组
 7      * low:数组的开始下标
 8      * hight:数组的末尾下标
 9      */
10     public void sort(int[] arras,int low,int hight){
11         int i = low;
12         int j = hight;
13         if(i>j){
14             return ;
15         }
16         //基准元素
17         int key = arras[low];
18         while(true){//让一趟里面的全部元素都比较完毕
19             //j往前走
20             while(j>i){
21                 if(arras[j] < key){
22                     //交换
23                     int temp = arras[j];
24                     arras[j] = arras[i];
25                     arras[i] = temp;
26                     break;
27                 }else{
28                     j--;
29                 }
30             }
31             //i往后走
32             while(j>i){
33                 if(arras[i] > key){
34                     //交换
35                     int temp = arras[j];
36                     arras[j] = arras[i];
37                     arras[i] = temp;
38                     break;
39                 }else{
40                     i++;
41                 }
42             }
43             if(i ==j){
44                 break;
45             }
46         }
47         //基准左边的数组排序
48         sort(arras,low,i-1);
49         //基准右边的数组排序
50         sort(arras,i+1,hight);
51     }
52     /*
53      * 打印数组里面的元素
54      */
55     public void print(int[] arras){
56         for(int i=0 ; i<arras.length;i++){
57             if(i==arras.length-1){
58                 System.out.println(arras[i]);
59             }else{
60                 System.out.print(arras[i]+",");
61             }
62         }
63     }
64     public static void main(String[] args) {
65         int[] as = {49,38,65,97,76,13,27};
66         QuicSort qs = new QuicSort();
67         qs.sort(as,0,as.length-1);
68         qs.print(as);
69     }
70 }

 1 package test1;
 2 
 3 public class QuickSort1 {
 4     int a[] = { 49, 38, 65, 97, 76, 13, 27, 49, 78, 34, 12, 64, 5, 4, 62, 99,
 5             98, 54, 56, 17, 18, 23, 34, 15, 35, 25, 53, 51 };
 6     public QuickSort1() {
 7         quick(a);
 8         for (int i = 0; i < a.length; i++)
 9             System.out.println(a[i]);
10     }
11     public int getMiddle(int[] list, int low, int high) {
12         int tmp = list[low]; // 数组的第一个作为中轴
13         while (low < high) {
14             while (low < high && list[high] >= tmp) {
15                 high--;
16             }
17             list[low] = list[high]; // 比中轴小的记录移到低端
18             while (low < high && list[low] <= tmp) {
19                 low++;
20             }
21             list[high] = list[low]; // 比中轴大的记录移到高端
22         }
23         list[low] = tmp; // 中轴记录到尾
24         return low; // 返回中轴的位置
25     }
26     public void _quickSort(int[] list, int low, int high) {
27         if (low < high) {
28             int middle = getMiddle(list, low, high); // 将list数组进行一分为二
29             _quickSort(list, low, middle - 1); // 对低字表进行递归排序
30             _quickSort(list, middle + 1, high); // 对高字表进行递归排序
31         }
32     }
33     public void quick(int[] a2) {
34         if (a2.length > 0) { // 查看数组是否为空
35             _quickSort(a2, 0, a2.length - 1);
36         }
37     }
38 }