量子猴排（Quantum Bogo sort）

Posted 2021-01-18 merryituxz

排序原理

原理很简单，如果数组不是有序的，就洗一次牌，直至数组有序为止

时间复杂度

最佳情况O(n)，平均情况O(n×n!)

 

代码如下：

 1 import java.util.Random;
 2 
 3 public class QuantumBogo {
 4     private static Random random = new Random();
 5 
 6     public static void sort(Comparable[] a){
 7 //        int count = 0;
 8         while (!isOrder(a)) {
 9             shuffle(a);
10 //            count++;
11         }
12     }
13 
14     private static boolean isOrder(Comparable[] a){
15         for (int i = 1; i < a.length; i++) {
16             if (a[i-1].compareTo(a[i]) > 0)
17                 return false;
18         }
19         return true;
20     }
21 
22     private static void shuffle(Comparable[] a){
23         int n = a.length;
24         for (int i = 0; i < n; i++) {
25             int r = i + random.nextInt(n-i);
26             Comparable temp = a[i];
27             a[i] = a[r];
28             a[r] = temp;
29         }
30     }
31 
32     private static void show(Comparable[] a){
33         for (int i = 0; i < a.length; i++)
34             System.out.print(a[i] + " ");
35         System.out.println();
36     }
37 
38     public static void main(String[] args){
39         Integer[] a = new Integer[12];
40         for (int i = 0; i < 12; i++) {
41             a[i] = random.nextInt(65536);
42         }
43         show(a);
44         sort(a);
45         show(a);
46     }
47 }