MathUtils.java

/**
 * Copyright (c) 2014-2017 by the respective copyright holders.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.eclipse.smarthome.model.core.internal.util;

/**
 * This class provides a few mathematical helper functions that are required by
 * code of this bundle.
 *
 * @author Kai Kreuzer - Initial contribution and API
 *
 */
public class MathUtils {

    /**
     * calculates the greatest common divisor of two numbers
     * 
     * @param m
     *            first number
     * @param n
     *            second number
     * @return the gcd of m and n
     */
    static public int gcd(int m, int n) {
        if (m % n == 0)
            return n;
        return gcd(n, m % n);
    }

    /**
     * calculates the least common multiple of two numbers
     * 
     * @param m
     *            first number
     * @param n
     *            second number
     * @return the lcm of m and n
     */
    static public int lcm(int m, int n) {
        return m * n / gcd(n, m);
    }

    /**
     * calculates the greatest common divisor of n numbers
     * 
     * @param numbers
     *            an array of n numbers
     * @return the gcd of the n numbers
     */
    static public int gcd(Integer[] numbers) {
        int n = numbers[0];
        for (int m : numbers) {
            n = gcd(n, m);
        }
        return n;
    }

    /**
     * determines the least common multiple of n numbers
     * 
     * @param numbers
     *            an array of n numbers
     * @return the least common multiple of all numbers of the array
     */
    static public int lcm(Integer[] numbers) {
        int n = numbers[0];
        for (int m : numbers) {
            n = lcm(n, m);
        }
        return n;
    }

}