Java Power of 2 nextPowerOfTwo(int x)

Here you can find the source of nextPowerOfTwo(int x)

Description

Return the least power of two greater than or equal to the specified value.

License

Apache License

Parameter

Parameter Description
x an integer smaller than or equal to 2<sup>30</sup>.

Return

the least power of two greater than or equal to the specified value.

Declaration

public static int nextPowerOfTwo(int x) 

Method Source Code

//package com.java2s;
/*/* w  ww .jav  a  2s  .  c o  m*/
 * Copyright (C) 2002-2011 Sebastiano Vigna
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    /** Return the least power of two greater than or equal to the specified value.
     *
     * <p>Note that this function will return 1 when the argument is 0.
     *
     * @param x an integer smaller than or equal to 2<sup>30</sup>.
     * @return the least power of two greater than or equal to the specified value.
     */
    public static int nextPowerOfTwo(int x) {
        if (x == 0)
            return 1;
        x--;
        x |= x >> 1;
        x |= x >> 2;
        x |= x >> 4;
        x |= x >> 8;
        return (x | x >> 16) + 1;
    }

    /** Return the least power of two greater than or equal to the specified value.
     *
     * <p>Note that this function will return 1 when the argument is 0.
     *
     * @param x a long integer smaller than or equal to 2<sup>62</sup>.
     * @return the least power of two greater than or equal to the specified value.
     */
    public static long nextPowerOfTwo(long x) {
        if (x == 0)
            return 1;
        x--;
        x |= x >> 1;
        x |= x >> 2;
        x |= x >> 4;
        x |= x >> 8;
        x |= x >> 16;
        return (x | x >> 32) + 1;
    }
}

Related

  1. nextPowerOfTwo(int x)
  2. nextPowerOfTwo(int x)
  3. nextPowerOfTwo(int x)
  4. nextPowerOfTwo(int x)
  5. nextPowerOfTwo(int x)
  6. nextPowerOfTwo(int x)
  7. nextPowerOfTwo(int x)
  8. nextPowerOfTwoExact(int n)
  9. nextPowerOfTwoValue(double value)