001    /*
002     * Copyright (C) 2008-2010 by Holger Arndt
003     *
004     * This file is part of the Universal Java Matrix Package (UJMP).
005     * See the NOTICE file distributed with this work for additional
006     * information regarding copyright ownership and licensing.
007     *
008     * UJMP is free software; you can redistribute it and/or modify
009     * it under the terms of the GNU Lesser General Public License as
010     * published by the Free Software Foundation; either version 2
011     * of the License, or (at your option) any later version.
012     *
013     * UJMP is distributed in the hope that it will be useful,
014     * but WITHOUT ANY WARRANTY; without even the implied warranty of
015     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016     * GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public
019     * License along with UJMP; if not, write to the
020     * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
021     * Boston, MA  02110-1301  USA
022     */
023    
024    package org.ujmp.core.util;
025    
026    import java.util.Random;
027    
028    public class RandomSimple extends Random {
029            private static final long serialVersionUID = -7454312208651558308L;
030    
031            private long x = 0;
032    
033            public RandomSimple() {
034                    this(System.nanoTime());
035            }
036    
037            public RandomSimple(long seed) {
038                    x = seed;
039            }
040    
041            public long nextLong() {
042                    x ^= (x << 21);
043                    x ^= (x >>> 35);
044                    x ^= (x << 4);
045                    return x;
046            }
047    
048            @Override
049            protected int next(int bits) {
050                    return (int) (nextLong() >>> (64 - bits));
051            }
052    
053    }