java实现的排序(插入/希尔/归并)

java实现三种简单的排序,以下是代码:

 1 /*插入排序*/
 2 public static void insertionSort(int[] a)
 3 {
 4     int j;
 5     for(int p = 1; p < a.length; p++)
 6     {
 7         int tmp = a[p];
 8         for(j = p; j > 0 && tmp < a[j - 1]; j--)
 9             a[j] = a[j - 1];
10         a[j] = tmp;
11     }
12 
13 }
14 //-----------------------------------------------------------  keleyi.com
15 /*希尔排序*/
16 public static void shellsort(int[] a)
17 {
18     int j;
19 
20     for(int gap = a.length / 2; gap > 0; gap /= 2)
21         for(int i = gap; i < a.length; i++)
22         {
23             int tmp = a[i];
24             for(j = i; j >= gap && tmp < a[j - gap]; j-=gap)
25                 a[j] = a[j - gap];
26             a[j] = tmp;
27         }
28 }
29 //-----------------------------------------------------------
30 /*归并排序*/
31 private static void mergeSort(int []a, int []tmpArray, int left, int right)
32 {
33     if(left < right)
34     {
35         int center = (left + right) / 2;
36         mergeSort(a, tmpArray, left, center);
37         mergeSort(a, tmpArray, center + 1, right);
38         merge(a, tmpArray, left, center + 1, right);
39     }
40 }
41 public static void mergeSort(int []a)
42 {
43     mergeSort(a, tmpArray, 0, a.length - 1);
44 }