/*

 * Copyright (c) 1998, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* @test

 * @bug 4181191

 * @summary test BigInteger modPow method

 */

import java.math.BigInteger;

import java.util.Random;

public class ModPow {

    public static void main(String[] args) {

        Random rnd = new Random(1234);

        for (int i=0; i<2000; i++) {

            BigInteger m = new BigInteger(800, rnd);

            BigInteger base = new BigInteger(16, rnd);

            if (rnd.nextInt() % 1 == 0)

                base = base.negate();

            BigInteger exp = new BigInteger(8, rnd);

            BigInteger z = base.modPow(exp, m);

            BigInteger w = base.pow(exp.intValue()).mod(m);

            if (!z.equals(w)){

                System.err.println(base +" ** " + exp + " mod "+ m);

                System.err.println("modPow : " + z);

                System.err.println("pow.mod: " + w);

                throw new RuntimeException("BigInteger modPow failure.");

            }

        }

    }

}