动手动脑

Posted 2021-01-12 mawangwang

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一，

完全“手写代码实现”随机数生成

例：在范围0~1000中生成20个随机数

 1 package 生成随机数;
 2 public class Suiji {
 3     private static final int N = 20;//生成随机数的个数
 4     private static final int LEFT = 0;//生成随机数的左范围
 5     private static final int RIGHT = 1000;//生成随机数的右范围
 6     private static long x0 = 1L;
 7     private long a = 1234567890L;
 8     private long c = 12345L;
 9     private long m = 2345678912L;     
10     // 产生随机数
11     private long rand ( long r )
12     {
13     // a,c,m为常数
14         r = ( r * a + c ) % m;//Xn+1=(aXn + c)mod m
15         return r;
16     }     
17     private long little ( int L, int R, long rand ){        
18         return L + rand % ( R - L + 1 );
19     }
20     int jishu=1;
21     private void recursion ( int count, long rand ){        
22         if (count >= N)    {            
23             return;
24         }
25         rand = rand (rand);
26         long r = little (LEFT, RIGHT, rand);        
27         System.out.print (r + "  ");       
28         recursion (++count, rand);
29     }
30     public static void main(String[] args) {        
31         Suiji a = new Suiji ();
32         a.recursion (0, x0);
33     }
34 }