Frequency.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
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 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
 * @test
 * @bug     4193200
 * @summary Basic test for Collections.frequency
 * @author  Josh Bloch
 */

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class Frequency {
    static final int N = 100;
    public static void main(String[] args) {
        test(new ArrayList<Integer>());
        test(new LinkedList<Integer>());
    }

    static void test(List<Integer> list) {
        for (int i = 0; i < N; i++)
            for (int j = 0; j < i; j++)
                list.add(i);
        Collections.shuffle(list);

        for (int i = 0; i < N; i++)
            if (Collections.frequency(list, i) != i)
                throw new RuntimeException(list.getClass() + ": " + i);
    }
}