Java BigInteger Calculate gcd(BigInteger... values)

Here you can find the source of gcd(BigInteger... values)

Description

Calculates the greatest common divisor of the specified BigInteger big integer numbers.

License

BSD License

Parameter

Parameter Description
values values for which the gcd is to be computed

Return

gcd of all values, negative if all values negative, zero if all values zero, positive otherwise

Declaration

public static BigInteger gcd(BigInteger... values) 

Method Source Code

//package com.java2s;
/*//from w  w  w.  j av a  2s  .co  m
 * =============================================================================
 * Simplified BSD License, see http://www.opensource.org/licenses/
 * -----------------------------------------------------------------------------
 * Copyright (c) 2008-2009, Marco Terzer, Zurich, Switzerland
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
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 *       this list of conditions and the following disclaimer.
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 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Swiss Federal Institute of Technology Zurich 
 *       nor the names of its contributors may be used to endorse or promote 
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 * =============================================================================
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import java.math.BigInteger;

public class Main {
    /**
     * Calculates the greatest common divisor of the specified {@link BigInteger 
     * big integer} numbers.
     * This method might be useful to scale down a vector of big integers. 
     * <p>
     * If all numbers are negative, the resulting gcd is also negative. If all 
     * numbers are zero, the result is zero. Otherwise, the result is positive.
     * 
     * @param values   values for which the gcd is to be computed
     * @return         gcd of all values, negative if all values negative, zero
     *                if all values zero, positive otherwise
     */
    public static BigInteger gcd(BigInteger... values) {
        if (values.length == 0)
            return BigInteger.ONE;
        int allSgn = values[0].signum();
        BigInteger gcd = values[0];
        for (int i = 1; i < values.length; i++) {
            if (allSgn != values[i].signum())
                allSgn = 1;
            if (gcd.signum() == 0 || gcd.equals(BigInteger.ONE))
                break;
            if (values[i].signum() != 0) {
                gcd = gcd.gcd(values[i]);
            }
        }
        if (allSgn == 0)
            return BigInteger.ZERO;
        if (allSgn < 0) {
            return gcd.negate();
        }
        return gcd;
    }
}

Related

  1. fill(BigInteger[] array, BigInteger value)
  2. first(BigInteger i, BigInteger j)
  3. firstLtSecond(BigInteger first, BigInteger second)
  4. gcd(BigInteger a, BigInteger b)
  5. GCD(BigInteger x, BigInteger y)
  6. gcd(Iterable nums)
  7. gcdEuclides(BigInteger a, BigInteger b)
  8. gcdExtended(BigInteger p, BigInteger q)
  9. getAddressText(BigInteger address)