/* * ZiffGFSR4.java * * Created on January 16, 2003, 11:47 PM * *  * Copyright (C) 2003 - Edwin S. Peer * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA  *   * This code is based on the implementation in GSL (GNU Scientific Library)  * which is also covered by the GNU General Public License. The original C  * source code is Copyright (C) 1998 James Theiler  *  */package net.sourceforge.cilib.Random;import java.util.*;/** * * @author  espeer */public class ZiffGFSR4 extends Random {        public ZiffGFSR4() {        super();    }        public ZiffGFSR4(long seed) {        super(seed);    }        private long LCG(long n) {        return (69069 * n) & 0xffffffffL;    }    public void setSeed(long seed) {        ra = new long[M + 1];                if (seed == 0) {            seed = 4357;        }                long msb = 0x80000000L;        long mask = 0xffffffffL;                for (int i = 0; i <= M; ++i) {            long t = 0;            long bit = msb;            for (int j = 0; j < 32; ++j) {                seed = LCG(seed);                if ((seed & msb) == msb) {                    t |= bit;                }                bit >>>= 1;            }            ra[i] = t;        }                for (int i = 0; i < 32; ++i) {            int k = 7 + i * 3;            ra[k] &= mask;            ra[k] |= msb;            mask >>>= 1;            msb >>>= 1;        }                nd = 32;    }        protected int next(int bits) {        nd = (nd + 1) & M;                 ra[nd] = ra[(nd + M + 1 - A) & M]               ^ ra[(nd + M + 1 - B) & M]               ^ ra[(nd + M + 1 - C) & M]               ^ ra[(nd + M + 1 - D) & M];                return (int) (ra[nd] >>> (32 - bits)) ;    }        private static final int A = 471;    private static final int B = 1586;    private static final int C = 6988;    private static final int D = 9689;    private static final int M = 16383;        private int nd;    private long[] ra;    }