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 }
