fork download
copy 
  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.util.stream.*;
  5. import java.util.concurrent.ThreadLocalRandom;
  6.  
  7. class Ideone {
  8. 	public static void main(String[] args) {
  9.  
  10.         Ranges r = new Ranges()
  11.             .add(3, 5)
  12.             .add(13, 16);
  13.  
  14.         Map<Long, Long> map = Stream.generate(() -> r.random())
  15.             .limit(1000000)
  16.             .collect(Collectors.groupingBy(i -> i, Collectors.counting()));
  17.  
  18.         map.forEach((k, v) -> System.out.println(k + ": " + v + "x"));
  19.  
  20. 	}
  21. }
  22.  
  23. class Ranges {
  24.  
  25.     private long offset;
  26.     private List<Long> offsets = new ArrayList<>();
  27.     private List<Range> ranges = new ArrayList<>();
  28.  
  29.     Ranges add(long min, long max) {
  30.         this.ranges.add(new Range(min, max));
  31.         this.offsets.add(offset);
  32.         this.offset += (max - min);
  33.         return this;
  34.     }
  35.  
  36.     long random() {
  37.         long index = ThreadLocalRandom.current().nextLong(this.offset);
  38.         int offsetIndex = Collections.binarySearch(this.offsets, index);
  39.         if (offsetIndex < 0) {
  40.             offsetIndex = Math.abs(offsetIndex) - 2;
  41.         }
  42.         Range r = this.ranges.get(offsetIndex);
  43.         return r.lower + index - this.offsets.get(offsetIndex);
  44.     }
  45. }
  46.  
  47. class Range {
  48.  
  49.     long lower;
  50.     long upper;
  51.  
  52.     Range(long lower, long upper) {
  53.         this.lower = lower;
  54.         this.upper = upper;
  55.     }
  56. }
Success #stdin #stdout 0.27s 2184192KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
3: 200516x
4: 199594x
13: 200430x
14: 199675x
15: 199785x
https://ideone.com/pjm5s6
language:
Java (HotSpot 12)
created:
6 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!