Description
Returns the log base 2 of an integer, rounded to the ceiling.
License
Open Source License
Parameter
Parameter | Description |
---|
i | The integer. |
Exception
Parameter | Description |
---|
IllegalArgumentException | if the integer passed in is zero or negative. |
Return
int the log base 2 of an integer, rounded to the ceiling.
Declaration
public static int ceilLogBaseTwo(final int i)
Method Source Code
//package com.java2s;
/*/*from ww w . j av a 2 s. co m*/
* Copyright Matt Palmer 2009-2014, All rights reserved.
*
* This code is licensed under a standard 3-clause BSD license:
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * 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.
*
* * The names of its contributors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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 HOLDER 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.
*/
public class Main {
/**
* Returns the log base 2 of an integer, rounded to the ceiling.
*
* Note that the integer must be positive.
*
* @param i The integer.
* @return int the log base 2 of an integer, rounded to the ceiling.
* @throws IllegalArgumentException if the integer passed in is zero or negative.
*/
public static int ceilLogBaseTwo(final int i) {
checkPositiveInteger(i);
return 32 - Integer.numberOfLeadingZeros(i - 1);
}
private static void checkPositiveInteger(final int value) {
if (value <= 0) {
throw new IllegalArgumentException("The value must be positive " + value);
}
}
}
Related
- ceilingPowerOf2(int n)
- ceilingPowerOfTwo(final int a)
- ceilingPowerOfTwo(int value)
- ceilInt(Double d, double intv)
- ceilInt(final double x)
- ceilMaskPOT(int n)
- ceilMultiple(float source, float multiple)
- ceilPositive(float x)
- ceilPoT(int arg)