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 }