package utility;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

/**
 * <h3>MersenneTwister and MersenneTwisterFast</h3>
 * <p>
 * <b>Version 20</b>, based on version MT199937(99/10/29) of the Mersenne Twister algorithm found at
 * <a href="http://www.math.keio.ac.jp/matumoto/emt.html"> The Mersenne Twister Home Page</a>, with
 * the initialization improved using the new 2002/1/26 initialization algorithm By Sean Luke,
 * October 2004.
 * 
 * <p>
 * <b>MersenneTwister</b> is a drop-in subclass replacement for java.util.Random. It is properly
 * synchronized and can be used in a multithreaded environment. On modern VMs such as HotSpot, it is
 * approximately 1/3 slower than java.util.Random.
 *
 * <p>
 * <b>MersenneTwisterFast</b> is not a subclass of java.util.Random. It has the same public methods
 * as Random does, however, and it is algorithmically identical to MersenneTwister.
 * MersenneTwisterFast has hard-code inlined all of its methods directly, and made all of them final
 * (well, the ones of consequence anyway). Further, these methods are <i>not</i> synchronized, so
 * the same MersenneTwisterFast instance cannot be shared by multiple threads. But all this helps
 * MersenneTwisterFast achieve well over twice the speed of MersenneTwister. java.util.Random is
 * about 1/3 slower than MersenneTwisterFast.
 *
 * <h3>About the Mersenne Twister</h3>
 * <p>
 * This is a Java version of the C-program for MT19937: Integer version. The MT19937 algorithm was
 * created by Makoto Matsumoto and Takuji Nishimura, who ask: "When you use this, send an email to:
 * matumoto@math.keio.ac.jp with an appropriate reference to your work". Indicate that this is a
 * translation of their algorithm into Java.
 *
 * <p>
 * <b>Reference. </b> Makato Matsumoto and Takuji Nishimura, "Mersenne Twister: A 623-Dimensionally
 * Equidistributed Uniform Pseudo-Random Number Generator", <i>ACM Transactions on Modeling and.
 * Computer Simulation,</i> Vol. 8, No. 1, January 1998, pp 3--30.
 *
 * <h3>About this Version</h3>
 *
 * <p>
 * <b>Changes since V19:</b> nextFloat(boolean, boolean) now returns float, not double.
 *
 * <p>
 * <b>Changes since V18:</b> Removed old final declarations, which used to potentially speed up the
 * code, but no longer.
 *
 * <p>
 * <b>Changes since V17:</b> Removed vestigial references to &= 0xffffffff which stemmed from the
 * original C code. The C code could not guarantee that ints were 32 bit, hence the masks. The
 * vestigial references in the Java code were likely optimized out anyway.
 *
 * <p>
 * <b>Changes since V16:</b> Added nextDouble(includeZero, includeOne) and nextFloat(includeZero,
 * includeOne) to allow for half-open, fully-closed, and fully-open intervals.
 *
 * <p>
 * <b>Changes Since V15:</b> Added serialVersionUID to quiet compiler warnings from Sun's overly
 * verbose compilers as of JDK 1.5.
 *
 * <p>
 * <b>Changes Since V14:</b> made strictfp, with StrictMath.log and StrictMath.sqrt in nextGaussian
 * instead of Math.log and Math.sqrt. This is largely just to be safe, as it presently makes no
 * difference in the speed, correctness, or results of the algorithm.
 *
 * <p>
 * <b>Changes Since V13:</b> clone() method CloneNotSupportedException removed.
 *
 * <p>
 * <b>Changes Since V12:</b> clone() method added.
 *
 * <p>
 * <b>Changes Since V11:</b> stateEquals(...) method added. MersenneTwisterFast is equal to other
 * MersenneTwisterFasts with identical state; likewise MersenneTwister is equal to other
 * MersenneTwister with identical state. This isn't equals(...) because that requires a contract of
 * immutability to compare by value.
 *
 * <p>
 * <b>Changes Since V10:</b> A documentation error suggested that setSeed(int[]) required an int[]
 * array 624 long. In fact, the array can be any non-zero length. The new version also checks for
 * this fact.
 *
 * <p>
 * <b>Changes Since V9:</b> readState(stream) and writeState(stream) provided.
 *
 * <p>
 * <b>Changes Since V8:</b> setSeed(int) was only using the first 28 bits of the seed; it should
 * have been 32 bits. For small-number seeds the behavior is identical.
 *
 * <p>
 * <b>Changes Since V7:</b> A documentation error in MersenneTwisterFast (but not MersenneTwister)
 * stated that nextDouble selects uniformly from the full-open interval [0,1]. It does not.
 * nextDouble's contract is identical across MersenneTwisterFast, MersenneTwister, and
 * java.util.Random, namely, selection in the half-open interval [0,1). That is, 1.0 should not be
 * returned. A similar contract exists in nextFloat.
 *
 * <p>
 * <b>Changes Since V6:</b> License has changed from LGPL to BSD. New timing information to compare
 * against java.util.Random. Recent versions of HotSpot have helped Random increase in speed to the
 * point where it is faster than MersenneTwister but slower than MersenneTwisterFast (which should
 * be the case, as it's a less complex algorithm but is synchronized).
 * 
 * <p>
 * <b>Changes Since V5:</b> New empty constructor made to work the same as java.util.Random --
 * namely, it seeds based on the current time in milliseconds.
 *
 * <p>
 * <b>Changes Since V4:</b> New initialization algorithms. See (see <a
 * href="http://www.math.keio.ac.jp/matumoto/MT2002/emt19937ar.html"</a>
 * http://www.math.keio.ac.jp/matumoto/MT2002/emt19937ar.html</a>)
 *
 * <p>
 * The MersenneTwister code is based on standard MT19937 C/C++ code by Takuji Nishimura, with
 * suggestions from Topher Cooper and Marc Rieffel, July 1997. The code was originally translated
 * into Java by Michael Lecuyer, January 1999, and the original code is Copyright (c) 1999 by
 * Michael Lecuyer.
 *
 * <h3>Java notes</h3>
 * 
 * <p>
 * This implementation implements the bug fixes made in Java 1.2's version of Random, which means it
 * can be used with earlier versions of Java. See <a
 * href="http://www.javasoft.com/products/jdk/1.2/docs/api/java/util/Random.html"> the JDK 1.2
 * java.util.Random documentation</a> for further documentation on the random-number generation
 * contracts made. Additionally, there's an undocumented bug in the JDK java.util.Random.nextBytes()
 * method, which this code fixes.
 *
 * <p>
 * Just like java.util.Random, this generator accepts a long seed but doesn't use all of it.
 * java.util.Random uses 48 bits. The Mersenne Twister instead uses 32 bits (int size). So it's best
 * if your seed does not exceed the int range.
 *
 * <p>
 * MersenneTwister can be used reliably on JDK version 1.1.5 or above. Earlier Java versions have
 * serious bugs in java.util.Random; only MersenneTwisterFast (and not MersenneTwister nor
 * java.util.Random) should be used with them.
 *
 * <h3>License</h3>
 *
 * Copyright (c) 2003 by Sean Luke. <br>
 * Portions copyright (c) 1993 by Michael Lecuyer. <br>
 * All rights reserved. <br>
 *
 * <p>
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 * <ul>
 * <li>Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 * <li>Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 * <li>Neither the name of the copyright owners, their employers, nor the names of its contributors
 * may be used to endorse or promote products derived from this software without specific prior
 * written permission.
 * </ul>
 * <p>
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNERS OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @version 20
 */

public strictfp class MersenneTwister
    extends java.util.Random
    implements Serializable, Cloneable
{
    // Serialization
    private static final long serialVersionUID = -4035832775130174188L; // locked as of Version 15

    // Period parameters
    private static final int N = 624;
    private static final int M = 397;
    private static final int MATRIX_A = 0x9908b0df; // private static final * constant vector a
    private static final int UPPER_MASK = 0x80000000; // most significant w-r bits
    private static final int LOWER_MASK = 0x7fffffff; // least significant r bits

    // Tempering parameters
    private static final int TEMPERING_MASK_B = 0x9d2c5680;
    private static final int TEMPERING_MASK_C = 0xefc60000;

    private int mt[]; // the array for the state vector
    private int mti; // mti==N+1 means mt[N] is not initialized
    private int mag01[];

    // a good initial seed (of int size, though stored in a long)
    // private static final long GOOD_SEED = 4357;

    /*
     * implemented here because there's a bug in Random's implementation of the Gaussian code
     * (divide by zero, and log(0), ugh!), yet its gaussian variables are private so we can't access
     * them here. :-(
     */

    private double __nextNextGaussian;
    private boolean __haveNextNextGaussian;

    /* We're overriding all internal data, to my knowledge, so this should be okay */
    public Object clone()
    {
        try {
            MersenneTwister f = (MersenneTwister) (super.clone());
            f.mt = (int[]) (mt.clone());
            f.mag01 = (int[]) (mag01.clone());
            return f;
        }
        catch (CloneNotSupportedException e) {
            throw new InternalError();
        } // should never happen
    }

    public boolean stateEquals(Object o)
    {
        if (o == this)
            return true;
        if (o == null || !(o instanceof MersenneTwister))
            return false;
        MersenneTwister other = (MersenneTwister) o;
        if (mti != other.mti)
            return false;
        for (int x = 0; x < mag01.length; x++)
            if (mag01[x] != other.mag01[x])
                return false;
        for (int x = 0; x < mt.length; x++)
            if (mt[x] != other.mt[x])
                return false;
        return true;
    }

    /** Reads the entire state of the MersenneTwister RNG from the stream */
    public void readState(DataInputStream stream)
        throws IOException
    {
        int len = mt.length;
        for (int x = 0; x < len; x++)
            mt[x] = stream.readInt();

        len = mag01.length;
        for (int x = 0; x < len; x++)
            mag01[x] = stream.readInt();

        mti = stream.readInt();
        __nextNextGaussian = stream.readDouble();
        __haveNextNextGaussian = stream.readBoolean();
    }

    /** Writes the entire state of the MersenneTwister RNG to the stream */
    public void writeState(DataOutputStream stream)
        throws IOException
    {
        int len = mt.length;
        for (int x = 0; x < len; x++)
            stream.writeInt(mt[x]);

        len = mag01.length;
        for (int x = 0; x < len; x++)
            stream.writeInt(mag01[x]);

        stream.writeInt(mti);
        stream.writeDouble(__nextNextGaussian);
        stream.writeBoolean(__haveNextNextGaussian);
    }

    /**
     * Constructor using the default seed.
     */
    public MersenneTwister()
    {
        this(System.currentTimeMillis());
    }

    /**
     * Constructor using a given seed. Though you pass this seed in as a long, it's best to make
     * sure it's actually an integer.
     */
    public MersenneTwister(long seed)
    {
        super(seed); /* just in case */
        setSeed(seed);
    }

    /**
     * Constructor using an array of integers as seed. Your array must have a non-zero length. Only
     * the first 624 integers in the array are used; if the array is shorter than this then integers
     * are repeatedly used in a wrap-around fashion.
     */
    public MersenneTwister(int[] array)
    {
        super(System.currentTimeMillis()); /* pick something at random just in case */
        setSeed(array);
    }

    /**
     * Initalize the pseudo random number generator. Don't pass in a long that's bigger than an int
     * (Mersenne Twister only uses the first 32 bits for its seed).
     */

    synchronized public void setSeed(long seed)
    {
        // it's always good style to call super
        super.setSeed(seed);

        // Due to a bug in java.util.Random clear up to 1.2, we're
        // doing our own Gaussian variable.
        __haveNextNextGaussian = false;

        mt = new int[N];

        mag01 = new int[2];
        mag01[0] = 0x0;
        mag01[1] = MATRIX_A;

        mt[0] = (int) (seed & 0xffffffff);
        mt[0] = (int) seed;
        for (mti = 1; mti < N; mti++) {
            mt[mti] = (1812433253 * (mt[mti - 1] ^ (mt[mti - 1] >>> 30)) + mti);
            /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
            /* In the previous versions, MSBs of the seed affect */
            /* only MSBs of the array mt[]. */
            /* 2002/01/09 modified by Makoto Matsumoto */
            // mt[mti] &= 0xffffffff;
            /* for >32 bit machines */
        }
    }

    /**
     * Sets the seed of the MersenneTwister using an array of integers. Your array must have a
     * non-zero length. Only the first 624 integers in the array are used; if the array is shorter
     * than this then integers are repeatedly used in a wrap-around fashion.
     */

    synchronized public void setSeed(int[] array)
    {
        if (array.length == 0)
            throw new IllegalArgumentException("Array length must be greater than zero");
        int i, j, k;
        setSeed(19650218);
        i = 1;
        j = 0;
        k = (N > array.length ? N : array.length);
        for (; k != 0; k--) {
            mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >>> 30)) * 1664525)) + array[j] + j; /*
                                                                                            * non
                                                                                            * linear
                                                                                            */
            // mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */
            i++;
            j++;
            if (i >= N) {
                mt[0] = mt[N - 1];
                i = 1;
            }
            if (j >= array.length)
                j = 0;
        }
        for (k = N - 1; k != 0; k--) {
            mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >>> 30)) * 1566083941)) - i; /* non linear */
            // mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */
            i++;
            if (i >= N) {
                mt[0] = mt[N - 1];
                i = 1;
            }
        }
        mt[0] = 0x80000000; /* MSB is 1; assuring non-zero initial array */
    }

    /**
     * Returns an integer with <i>bits</i> bits filled with a random number.
     */
    synchronized protected int next(int bits)
    {
        int y;

        if (mti >= N) // generate N words at one time
        {
            int kk;
            final int[] mt = this.mt; // locals are slightly faster
            final int[] mag01 = this.mag01; // locals are slightly faster

            for (kk = 0; kk < N - M; kk++) {
                y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
                mt[kk] = mt[kk + M] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            for (; kk < N - 1; kk++) {
                y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
                mt[kk] = mt[kk + (M - N)] ^ (y >>> 1) ^ mag01[y & 0x1];
            }
            y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
            mt[N - 1] = mt[M - 1] ^ (y >>> 1) ^ mag01[y & 0x1];

            mti = 0;
        }

        y = mt[mti++];
        y ^= y >>> 11; // TEMPERING_SHIFT_U(y)
        y ^= (y << 7) & TEMPERING_MASK_B; // TEMPERING_SHIFT_S(y)
        y ^= (y << 15) & TEMPERING_MASK_C; // TEMPERING_SHIFT_T(y)
        y ^= (y >>> 18); // TEMPERING_SHIFT_L(y)

        return y >>> (32 - bits); // hope that's right!
    }

    /*
     * If you've got a truly old version of Java, you can omit these two next methods.
     */

    private synchronized void writeObject(ObjectOutputStream out)
        throws IOException
    {
        // just so we're synchronized.
        out.defaultWriteObject();
    }

    private synchronized void readObject(ObjectInputStream in)
        throws IOException, ClassNotFoundException
    {
        // just so we're synchronized.
        in.defaultReadObject();
    }

    /**
     * This method is missing from jdk 1.0.x and below. JDK 1.1 includes this for us, but what the
     * heck.
     */
    public boolean nextBoolean()
    {
        return next(1) != 0;
    }

    /**
     * This generates a coin flip with a probability <tt>probability</tt> of returning true, else
     * returning false. <tt>probability</tt> must be between 0.0 and 1.0, inclusive. Not as precise
     * a random real event as nextBoolean(double), but twice as fast. To explicitly use this,
     * remember you may need to cast to float first.
     */

    public boolean nextBoolean(float probability)
    {
        if (probability < 0.0f || probability > 1.0f)
            throw new IllegalArgumentException("probability must be between 0.0 and 1.0 inclusive.");
        if (probability == 0.0f)
            return false; // fix half-open issues
        else if (probability == 1.0f)
            return true; // fix half-open issues
        return nextFloat() < probability;
    }

    /**
     * This generates a coin flip with a probability <tt>probability</tt> of returning true, else
     * returning false. <tt>probability</tt> must be between 0.0 and 1.0, inclusive.
     */

    public boolean nextBoolean(double probability)
    {
        if (probability < 0.0 || probability > 1.0)
            throw new IllegalArgumentException("probability must be between 0.0 and 1.0 inclusive.");
        if (probability == 0.0)
            return false; // fix half-open issues
        else if (probability == 1.0)
            return true; // fix half-open issues
        return nextDouble() < probability;
    }

    /**
     * This method is missing from JDK 1.1 and below. JDK 1.2 includes this for us, but what the
     * heck.
     */

    public int nextInt(int n)
    {
        if (n <= 0)
            throw new IllegalArgumentException("n must be positive, got: " + n);

        if ((n & -n) == n)
            return (int) ((n * (long) next(31)) >> 31);

        int bits, val;
        do {
            bits = next(31);
            val = bits % n;
        }
        while (bits - val + (n - 1) < 0);
        return val;
    }

    /**
     * This method is for completness' sake. Returns a long drawn uniformly from 0 to n-1. Suffice
     * it to say, n must be > 0, or an IllegalArgumentException is raised.
     */

    public long nextLong(long n)
    {
        if (n <= 0)
            throw new IllegalArgumentException("n must be positive, got: " + n);

        long bits, val;
        do {
            bits = (nextLong() >>> 1);
            val = bits % n;
        }
        while (bits - val + (n - 1) < 0);
        return val;
    }

    /**
     * A bug fix for versions of JDK 1.1 and below. JDK 1.2 fixes this for us, but what the heck.
     */
    public double nextDouble()
    {
        return (((long) next(26) << 27) + next(27)) / (double) (1L << 53);
    }

    /**
     * Returns a double in the range from 0.0 to 1.0, possibly inclusive of 0.0 and 1.0 themselves.
     * Thus:
     * 
     * <p>
     * <table border=0>
     * <th>
     * <td>Expression
     * <td>Interval
     * <tr>
     * <td>nextDouble(false, false)
     * <td>(0.0, 1.0)
     * <tr>
     * <td>nextDouble(true, false)
     * <td>[0.0, 1.0)
     * <tr>
     * <td>nextDouble(false, true)
     * <td>(0.0, 1.0]
     * <tr>
     * <td>nextDouble(true, true)
     * <td>[0.0, 1.0]
     * </table>
     * 
     * <p>
     * This version preserves all possible random values in the double range.
     */
    public double nextDouble(boolean includeZero, boolean includeOne)
    {
        double d = 0.0;
        do {
            d = nextDouble(); // grab a value, initially from half-open [0.0, 1.0)
            if (includeOne && nextBoolean())
                d += 1.0; // if includeOne, with 1/2 probability, push to [1.0, 2.0)
        }
        while ((d > 1.0) || // everything above 1.0 is always invalid
                (!includeZero && d == 0.0)); // if we're not including zero, 0.0 is invalid
        return d;
    }

    /**
     * A bug fix for versions of JDK 1.1 and below. JDK 1.2 fixes this for us, but what the heck.
     */

    public float nextFloat()
    {
        return next(24) / ((float) (1 << 24));
    }

    /**
     * Returns a float in the range from 0.0f to 1.0f, possibly inclusive of 0.0f and 1.0f
     * themselves. Thus:
     * 
     * <p>
     * <table border=0>
     * <th>
     * <td>Expression
     * <td>Interval
     * <tr>
     * <td>nextFloat(false, false)
     * <td>(0.0f, 1.0f)
     * <tr>
     * <td>nextFloat(true, false)
     * <td>[0.0f, 1.0f)
     * <tr>
     * <td>nextFloat(false, true)
     * <td>(0.0f, 1.0f]
     * <tr>
     * <td>nextFloat(true, true)
     * <td>[0.0f, 1.0f]
     * </table>
     * 
     * <p>
     * This version preserves all possible random values in the float range.
     */
    public float nextFloat(boolean includeZero, boolean includeOne)
    {
        float d = 0.0f;
        do {
            d = nextFloat(); // grab a value, initially from half-open [0.0f, 1.0f)
            if (includeOne && nextBoolean())
                d += 1.0f; // if includeOne, with 1/2 probability, push to [1.0f, 2.0f)
        }
        while ((d > 1.0f) || // everything above 1.0f is always invalid
                (!includeZero && d == 0.0f)); // if we're not including zero, 0.0f is invalid
        return d;
    }

    /**
     * A bug fix for all versions of the JDK. The JDK appears to use all four bytes in an integer as
     * independent byte values! Totally wrong. I've submitted a bug report.
     */

    public void nextBytes(byte[] bytes)
    {
        for (int x = 0; x < bytes.length; x++)
            bytes[x] = (byte) next(8);
    }

    /** For completeness' sake, though it's not in java.util.Random. */

    public char nextChar()
    {
        // chars are 16-bit UniCode values
        return (char) (next(16));
    }

    /** For completeness' sake, though it's not in java.util.Random. */

    public short nextShort()
    {
        return (short) (next(16));
    }

    /** For completeness' sake, though it's not in java.util.Random. */

    public byte nextByte()
    {
        return (byte) (next(8));
    }

    /**
     * A bug fix for all JDK code including 1.2. nextGaussian can theoretically ask for the log of 0
     * and divide it by 0! See Java bug <a
     * href="http://developer.java.sun.com/developer/bugParade/bugs/4254501.html">
     * http://developer.java.sun.com/developer/bugParade/bugs/4254501.html</a>
     */

    synchronized public double nextGaussian()
    {
        if (__haveNextNextGaussian) {
            __haveNextNextGaussian = false;
            return __nextNextGaussian;
        }
        else {
            double v1, v2, s;
            do {
                v1 = 2 * nextDouble() - 1; // between -1.0 and 1.0
                v2 = 2 * nextDouble() - 1; // between -1.0 and 1.0
                s = v1 * v1 + v2 * v2;
            }
            while (s >= 1 || s == 0);
            double multiplier = StrictMath.sqrt(-2 * StrictMath.log(s) / s);
            __nextNextGaussian = v2 * multiplier;
            __haveNextNextGaussian = true;
            return v1 * multiplier;
        }
    }

    /**
     * Tests the code.
     */
    public static void main(String args[])
    {
        int j;

        MersenneTwister r;

        // CORRECTNESS TEST
        // COMPARE WITH http://www.math.keio.ac.jp/matumoto/CODES/MT2002/mt19937ar.out

        r = new MersenneTwister(new int[] { 0x123, 0x234, 0x345, 0x456 });
        System.out.println("Output of MersenneTwister with new (2002/1/26) seeding mechanism");
        for (j = 0; j < 1000; j++) {
            // first, convert the int from signed to "unsigned"
            long l = (long) r.nextInt();
            if (l < 0)
                l += 4294967296L; // max int value
            String s = String.valueOf(l);
            while (s.length() < 10)
                s = " " + s; // buffer
            System.out.print(s + " ");
            if (j % 5 == 4)
                System.out.println();
        }

        // SPEED TEST

        final long SEED = 4357;

        int xx;
        long ms;
        System.out.println("\nTime to test grabbing 100000000 ints");

        r = new MersenneTwister(SEED);
        ms = System.currentTimeMillis();
        xx = 0;
        for (j = 0; j < 100000000; j++)
            xx += r.nextInt();
        System.out.println("Mersenne Twister: " + (System.currentTimeMillis() - ms)
                + "          Ignore this: " + xx);

        System.out
                .println("To compare this with java.util.Random, run this same test on MersenneTwisterFast.");
        System.out
                .println("The comparison with Random is removed from MersenneTwister because it is a proper");
        System.out
                .println("subclass of Random and this unfairly makes some of Random's methods un-inlinable,");
        System.out.println("so it would make Random look worse than it is.");

        // TEST TO COMPARE TYPE CONVERSION BETWEEN
        // MersenneTwisterFast.java AND MersenneTwister.java

        System.out.println("\nGrab the first 1000 booleans");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextBoolean() + " ");
            if (j % 8 == 7)
                System.out.println();
        }
        if (!(j % 8 == 7))
            System.out.println();

        System.out
                .println("\nGrab 1000 booleans of increasing probability using nextBoolean(double)");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextBoolean((double) (j / 999.0)) + " ");
            if (j % 8 == 7)
                System.out.println();
        }
        if (!(j % 8 == 7))
            System.out.println();

        System.out
                .println("\nGrab 1000 booleans of increasing probability using nextBoolean(float)");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextBoolean((float) (j / 999.0f)) + " ");
            if (j % 8 == 7)
                System.out.println();
        }
        if (!(j % 8 == 7))
            System.out.println();

        byte[] bytes = new byte[1000];
        System.out.println("\nGrab the first 1000 bytes using nextBytes");
        r = new MersenneTwister(SEED);
        r.nextBytes(bytes);
        for (j = 0; j < 1000; j++) {
            System.out.print(bytes[j] + " ");
            if (j % 16 == 15)
                System.out.println();
        }
        if (!(j % 16 == 15))
            System.out.println();

        byte b;
        System.out.println("\nGrab the first 1000 bytes -- must be same as nextBytes");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print((b = r.nextByte()) + " ");
            if (b != bytes[j])
                System.out.print("BAD ");
            if (j % 16 == 15)
                System.out.println();
        }
        if (!(j % 16 == 15))
            System.out.println();

        System.out.println("\nGrab the first 1000 shorts");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextShort() + " ");
            if (j % 8 == 7)
                System.out.println();
        }
        if (!(j % 8 == 7))
            System.out.println();

        System.out.println("\nGrab the first 1000 ints");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextInt() + " ");
            if (j % 4 == 3)
                System.out.println();
        }
        if (!(j % 4 == 3))
            System.out.println();

        System.out.println("\nGrab the first 1000 ints of different sizes");
        r = new MersenneTwister(SEED);
        int max = 1;
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextInt(max) + " ");
            max *= 2;
            if (max <= 0)
                max = 1;
            if (j % 4 == 3)
                System.out.println();
        }
        if (!(j % 4 == 3))
            System.out.println();

        System.out.println("\nGrab the first 1000 longs");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextLong() + " ");
            if (j % 3 == 2)
                System.out.println();
        }
        if (!(j % 3 == 2))
            System.out.println();

        System.out.println("\nGrab the first 1000 longs of different sizes");
        r = new MersenneTwister(SEED);
        long max2 = 1;
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextLong(max2) + " ");
            max2 *= 2;
            if (max2 <= 0)
                max2 = 1;
            if (j % 4 == 3)
                System.out.println();
        }
        if (!(j % 4 == 3))
            System.out.println();

        System.out.println("\nGrab the first 1000 floats");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextFloat() + " ");
            if (j % 4 == 3)
                System.out.println();
        }
        if (!(j % 4 == 3))
            System.out.println();

        System.out.println("\nGrab the first 1000 doubles");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextDouble() + " ");
            if (j % 3 == 2)
                System.out.println();
        }
        if (!(j % 3 == 2))
            System.out.println();

        System.out.println("\nGrab the first 1000 gaussian doubles");
        r = new MersenneTwister(SEED);
        for (j = 0; j < 1000; j++) {
            System.out.print(r.nextGaussian() + " ");
            if (j % 3 == 2)
                System.out.println();
        }
        if (!(j % 3 == 2))
            System.out.println();

    }

}
