排序算法Java实现（堆排序）

 1 package sorting;
 2 
 3 /**
 4  * 堆排序
 5  * 平均O(nlogn),最好O(nlogn),最坏O(nlogn);空间复杂度O(1);不稳定;较复杂
 6  * @author zeng
 7  *
 8  */
 9 public class DuiPaixu {
10 
11     public static void duipaixu(int[] a) {
12         int i, tmp;
13         for (i = a.length / 2; i >= 1; i--)
14             HeapAdjust(a, i, a.length);
15         for (i = a.length; i > 1; i--) {
16             tmp = a[0];
17             a[0] = a[i - 1];
18             a[i - 1] = tmp;
19             HeapAdjust(a, 1, i - 1);
20             for (int j : a)
21                 System.out.print(j + " ");
22             System.out.println();
23         }
24     }
25 
26     public static void HeapAdjust(int A[], int i, int length) {
27         int j = 2 * i;
28         int tmp = A[i - 1];
29         while (j <= length) {
30             if (j < length && A[j - 1] < A[j])
31                 j++;
32             if (A[j - 1] > tmp) {
33                 A[i - 1] = A[j - 1];
34                 i = j;
35                 j = 2 * i;
36             } else {
37                 break;
38             }
39         }
40         A[i - 1] = tmp;
41     }
42 
43     public static void main(String[] args) {
44         int[] b = { 49, 38, 65, 97, 76, 13, 27, 50 };
45         duipaixu(b);
46         for (int i : b)
47             System.out.print(i + " ");
48 
49     }
50 
51 }