Java Number Power pow(double x, int n)

Description

This is a fast pow implementation

License

Open Source License

Parameter

Parameter	Description
x	the base
n	the exponent

Return

the n-th power of x

Declaration

public static double pow(double x, int n) 

Method Source Code

//package com.java2s;
/**//w w w. ja va 2  s  . c  o  m
 * This file is part of CubeEngine.
 * CubeEngine is licensed under the GNU General Public License Version 3.
 *
 * CubeEngine is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * CubeEngine is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with CubeEngine.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Main {
    /**
     * This is a fast pow implementation
     *
     * @param x the base
     * @param n the exponent
     * @return the n-th power of x
     */
    public static double pow(double x, int n) {
        if (n == 0) {
            return 1.0;
        }
        for (int i = 1; i < n; ++i) {
            x *= x;
        }
        return x;
    }

    /**
     * This is a fast pow implementation for int values
     *
     * @param x the base
     * @param n the exponent
     * @return the n-th power of x
     */
    public static double pow(int x, int n) {
        double result = 1.0;
        while (n != 0) {
            if ((x & 1) == 1) {
                result *= x;
                --n;
            }
            x *= x;
            n /= 2;
        }
        return result;
    }
}

Related

1. Pow(double value)
2. pow(double value)
3. pow(double x, double y)
4. pow(double x, double y)
5. pow(double x, double y)
6. pow(double[] array, double exp)
7. pow(double[][] x, int p)
8. pow(final double[] values, final double exp)
9. pow(final float a, final float b)