1 package log;
2
3 import java.util.Arrays;
4
5 public class Test4 {
6
7 /**
8 * java算法---归并排序
9 *
10 * @param args
11 */
12 public static void main(String[] args) {
13 // 需要排序的数组
14 int arr[] = { 49, 20, 36, 51, 18, 94, 61, 31, 50
};
15 // 循环输出该数组内容
16 System.out.println("排序之前："
);
17 for (
int a : arr) {
18 System.out.print(a + "\t"
);
19 }
20 System.out.println();
21
22 sort(arr, 0, arr.length - 1
);
23 // 循环输出该数组内容
24 System.out.println("排序之后："
);
25 for (
int a : arr) {
26 System.out.print(a + "\t"
);
27 }
28 System.out.println();
29
30 }
31
32 public static void merge(
int[] list,
int left,
int center,
int right) {
33 int[] tempArr =
new int[list.length];
34 int mid = center + 1
;
35 int third =
left;
36 int temp =
left;
37 while (left <= center && mid <=
right) {
38 if (list[left] <=
list[mid]) {
39 tempArr[third++] = list[left++
];
40 }
else {
41 tempArr[third++] = list[mid++
];
42 }
43 }
44 while (mid <=
right) {
45 tempArr[third++] = list[mid++
];
46 }
47 while (left <=
center) {
48 tempArr[third++] = list[left++
];
49 }
50 while (temp <=
right) {
51 list[temp] = tempArr[temp++
];
52 }
53 System.out.println(Arrays.toString(list));
54 }
55
56 public static void sort(
int[] list,
int left,
int right) {
57 if (left <
right) {
58 int center = (left + right) / 2
;
59 sort(list, left, center);
60 sort(list, center + 1
, right);
61 merge(list, left, center, right);
62 }
63 }
64
65 }
下面是控制台的输出结果
归并排序是将两个或者两个以上有序表合并成一个新的有序表，即把带排序序列分为若干个子序列，每个子序列都是有序的。然后再把有序子序列合并为整体有序序列。
转载于:https://www.cnblogs.com/javallh/p/8762294.html
