1 /*
   2  * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package vm.compiler.share;
  24 
  25 public class Random {
  26     private int current;
  27 
  28     public Random(int init) {
  29         this.current =  init;
  30     }
  31 
  32     //big prime number
  33     private static long BASE = 1003001;
  34 
  35     public int nextInt() {
  36         current = (int) ((long) current * current % BASE - 1);
  37         return current;
  38     }
  39 
  40     public int nextInt(int n) {
  41         return nextInt() % n;
  42     }
  43 
  44 
  45     /**
  46      * for testing purposes
  47      * @param args
  48      */
  49     public static void main(String[] args) {
  50         Random r = new Random(11);
  51         int[] a = new int[100];
  52 
  53         for(int i=0; i<1000; i++) {
  54             a[r.nextInt(100)]++;
  55         }
  56 
  57         for(int i=0; i<100; i++){
  58             System.out.println(times(a[i]));
  59         }
  60 
  61     }
  62 
  63     public static String times(int n) {
  64         StringBuilder sb = new StringBuilder();
  65         for(int i=0; i<n; i++) {
  66             sb.append("*");
  67         }
  68         return sb.toString();
  69     }
  70 }