1/*
2 * Copyright (c) 2003, 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
24/*
25 * @test
26 * @bug     4339792
27 * @summary Basic test for Collections.disjoint
28 * @author  Josh Bloch
29 * @key randomness
30 */
31
32import java.util.*;
33
34public class Disjoint {
35    static final int N = 20;
36
37    public static void main(String args[]) {
38        // Make an array of lists each of which shares a single element
39        // with its "neighbors," and no elements with other lists in the array
40        Random rnd = new Random();
41        List[] lists = new List[N];
42        int x = 0;
43        for (int i = 0; i < N; i++) {
44            int size = rnd.nextInt(10) + 2;
45            List<Integer> list = new ArrayList<>(size);
46            for (int j = 1; j < size; j++)
47                list.add(x++);
48            list.add(x);
49            Collections.shuffle(list);
50
51            lists[i] = list;
52        }
53
54        for (int i = 0; i < N; i++) {
55            for (int j = 0; j < N; j++) {
56                boolean disjoint = (Math.abs(i - j) > 1);
57                List<Integer> a = (List<Integer>) lists[i];
58                List<Integer> b = (List<Integer>) lists[j];
59
60                if (Collections.disjoint(a, b) != disjoint)
61                    throw new RuntimeException("A: " + i + ", " + j);
62                if (Collections.disjoint(new HashSet<Integer>(a), b)
63                    != disjoint)
64                    throw new RuntimeException("B: " + i + ", " + j);
65                if (Collections.disjoint(new HashSet<Integer>(a),
66                                         new HashSet<Integer>(b)) != disjoint)
67                    throw new RuntimeException("C: " + i + ", " + j);
68            }
69        }
70    }
71}
72