1 /*
   2  * Copyright 2003 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug     4339792
  27  * @summary Basic test for Collections.disjoint
  28  * @author  Josh Bloch
  29  */
  30 
  31 import java.util.*;
  32 
  33 public class Disjoint {
  34     final static int N = 20;
  35 
  36     public static void main(String args[]) {
  37         // Make an array of lists each of which shares a single element
  38         // with its "neighbors," and no elements with other lists in the array
  39         Random rnd = new Random();
  40         List[] lists = new List[N];
  41         int x = 0;
  42         for (int i = 0; i < N; i++) {
  43             int size = rnd.nextInt(10) + 2;
  44             List<Integer> list = new ArrayList<Integer>(size);
  45             for (int j = 1; j < size; j++)
  46                 list.add(x++);
  47             list.add(x);
  48             Collections.shuffle(list);
  49 
  50             lists[i] = list;
  51         }
  52 
  53         for (int i = 0; i < N; i++) {
  54             for (int j = 0; j < N; j++) {
  55                 boolean disjoint = (Math.abs(i - j) > 1);
  56                 List<Integer> a = (List<Integer>) lists[i];
  57                 List<Integer> b = (List<Integer>) lists[j];
  58 
  59                 if (Collections.disjoint(a, b) != disjoint)
  60                     throw new RuntimeException("A: " + i + ", " + j);
  61                 if (Collections.disjoint(new HashSet<Integer>(a), b)
  62                     != disjoint)
  63                     throw new RuntimeException("B: " + i + ", " + j);
  64                 if (Collections.disjoint(new HashSet<Integer>(a),
  65                                          new HashSet<Integer>(b)) != disjoint)
  66                     throw new RuntimeException("C: " + i + ", " + j);
  67             }
  68         }
  69     }
  70 }