Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/* ***** BEGIN LICENSE BLOCK *****
 * JTransforms
 * Copyright (c) 2007 onward, Piotr Wendykier
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer. 
 * 2. 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.
 *
 * 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 OWNER 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.
 *
 * ***** END LICENSE BLOCK ***** */

public class Main {
    /**
     * Returns the closest power-of-two number less than or equal to x.
     *
     * @param x input value
     *
     * @return the closest power-of-two number less then or equal to x
     */
    public static int prevPow2(int x) {
        if (x < 1) {
            throw new IllegalArgumentException("x must be greater or equal 1");
        }
        return (int) Math.pow(2, Math.floor(Math.log(x) / Math.log(2)));
    }

    /**
     * Returns the closest power-of-two number less than or equal to x.
     *
     * @param x input value
     *
     * @return the closest power-of-two number less then or equal to x
     */
    public static long prevPow2(long x) {
        if (x < 1) {
            throw new IllegalArgumentException("x must be greater or equal 1");
        }
        return (long) Math.pow(2, Math.floor(Math.log(x) / Math.log(2)));
    }
}