1 package log;
2
3 import java.util.Arrays;
4
5 public class Test4 {
6 /**
7 * 堆排序
8 *
9 * @param args
10 */
11 public static void main(String[] args) {
12 int arr[] = { 49, 20, 36, 51, 18, 94, 61, 31, 50
};
13
14 // 循环输出该数组内容
15 System.out.println("排序之前："
);
16 for (
int a : arr) {
17 System.out.print(a + "\t"
);
18 }
19 System.out.println();
20
21 int arrlength =
arr.length;
22
23 // 循环建堆
24 for (
int i = 0; i < arrlength - 1; i++
) {
25 build(arr, arrlength - 1 -
i);
26 swap(arr, 0, arrlength - 1 -
i);
27 System.out.println(Arrays.toString(arr));
28 }
29
30 // 循环输出该数组内容
31 System.out.println("排序之后："
);
32 for (
int a : arr) {
33 System.out.print(a + "\t"
);
34 }
35 System.out.println();
36
37 }
38
39 private static void build(
int[] data,
int lastIndex) {
40 for (
int i = (lastIndex - 1) / 2; i >= 0; i--
) {
41 int k =
i;
42 while (k * 2 + 1 <=
lastIndex) {
43 int bigIndex = 2 * k + 1
;
44 if (bigIndex <
lastIndex) {
45 if (data[bigIndex] < data[bigIndex + 1
]) {
46 bigIndex++
;
47 }
48 }
49
50 if (data[k] <
data[bigIndex]) {
51 swap(data, k, bigIndex);
52 k =
bigIndex;
53 }
else {
54 break;
55 }
56
57 }
58 }
59 }
60
61 private static void swap(
int[] data,
int i,
int j) {
62 int temp =
data[i];
63 data[i] =
data[j];
64 data[j] =
temp;
65 }
66
67 }
下面是控制台的输出
转载于:https://www.cnblogs.com/javallh/p/8781942.html
