user/test/com/google/gwt/emultest/java/math/BigIntegerMultiplyTest.java

/*
 * Copyright 2009 Google Inc.
 * 
 * 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.
 */

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You 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.
 * 
 * INCLUDES MODIFICATIONS BY GOOGLE.
 */
/**
 * author Elena Semukhina
 */
package com.google.gwt.emultest.java.math;

import com.google.gwt.emultest.java.util.EmulTestBase;

import java.math.BigInteger;

/**
 * Class: java.math.BigInteger Method: multiply.
 */
public class BigIntegerMultiplyTest extends EmulTestBase {
  /**
   * Multiply two negative numbers of the same length.
   */
  public void testCase1() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = -1;
    int bSign = -1;
    byte rBytes[] = {
        10, 40, 100, -55, 96, 51, 76, 40, -45, 85, 105, 4, 28, -86, -117, -52,
        100, 120, 90};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Multiply a negative number by ONE.
   */
  public void testCase10() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    int aSign = -1;
    byte rBytes[] = {-2, -3, -4, -5, -6, -7, -8, -2, -3, -4, -2, -3, -4, -5, -5};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = BigInteger.ONE;
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Multiply two numbers of the same length and different signs. The first is
   * negative.
   */
  public void testCase2() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = -1;
    int bSign = 1;
    byte rBytes[] = {
        -11, -41, -101, 54, -97, -52, -77, -41, 44, -86, -106, -5, -29, 85,
        116, 51, -101, -121, -90};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Multiply two positive numbers of different length. The first is longer.
   */
  public void testCase3() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {
        10, 40, 100, -55, 96, 51, 76, 40, -45, 85, 115, 44, -127, 115, -21,
        -62, -15, 85, 64, -87, -2, -36, -36, -106};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Multiply two positive numbers of different length. The second is longer.
   */
  public void testCase4() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {
        10, 40, 100, -55, 96, 51, 76, 40, -45, 85, 115, 44, -127, 115, -21,
        -62, -15, 85, 64, -87, -2, -36, -36, -106};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Multiply two numbers of different length and different signs. The first is
   * positive. The first is longer.
   */
  public void testCase5() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {
        -11, -41, -101, 54, -97, -52, -77, -41, 44, -86, -116, -45, 126, -116,
        20, 61, 14, -86, -65, 86, 1, 35, 35, 106};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Multiply two numbers of different length and different signs. The first is
   * positive. The second is longer.
   */
  public void testCase6() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {
        -11, -41, -101, 54, -97, -52, -77, -41, 44, -86, -116, -45, 126, -116,
        20, 61, 14, -86, -65, 86, 1, 35, 35, 106};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Multiply a number by zero.
   */
  public void testCase7() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    byte bBytes[] = {0};
    int aSign = 1;
    int bSign = 0;
    byte rBytes[] = {0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 0, result.signum());
  }

  /**
   * Multiply a number by ZERO.
   */
  public void testCase8() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    int aSign = 1;
    byte rBytes[] = {0};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = BigInteger.ZERO;
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 0, result.signum());
  }

  /**
   * Multiply a positive number by ONE.
   */
  public void testCase9() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    int aSign = 1;
    byte rBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 1, 2, 3, 4, 5};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = BigInteger.ONE;
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Multiply two numbers of 4 bytes length.
   */
  public void testIntbyInt1() {
    byte aBytes[] = {10, 20, 30, 40};
    byte bBytes[] = {1, 2, 3, 4};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {-11, -41, -101, 55, 5, 15, 96};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Multiply two numbers of 4 bytes length.
   */
  public void testIntbyInt2() {
    byte aBytes[] = {-1, -1, -1, -1};
    byte bBytes[] = {-1, -1, -1, -1};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {0, -1, -1, -1, -2, 0, 0, 0, 1};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.multiply(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Negative exponent.
   */
  public void testPowException() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7};
    int aSign = 1;
    int exp = -5;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    try {
      aNumber = aNumber.pow(exp);
      fail("ArithmeticException has not been caught");
    } catch (ArithmeticException e) {
      assertEquals("Improper exception message", "Negative exponent",
          e.getMessage());
    }
  }

  /**
   * Exponentiation of a negative number to an even exponent.
   */
  public void testPowNegativeNumToEvenExp() {
    byte aBytes[] = {50, -26, 90, 69, 120, 32, 63, -103, -14, 35};
    int aSign = -1;
    int exp = 4;
    byte rBytes[] = {
        102, 107, -122, -43, -52, -20, -27, 25, -9, 88, -13, 75, 78, 81, -33,
        -77, 39, 27, -37, 106, 121, -73, 108, -47, -101, 80, -25, 71, 13, 94,
        -7, -33, 1, -17, -65, -70, -61, -3, -47};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.pow(exp);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Exponentiation of a negative number to an odd exponent.
   */
  public void testPowNegativeNumToOddExp() {
    byte aBytes[] = {50, -26, 90, 69, 120, 32, 63, -103, -14, 35};
    int aSign = -1;
    int exp = 5;
    byte rBytes[] = {
        -21, -94, -42, -15, -127, 113, -50, -88, 115, -35, 3, 59, -92, 111,
        -75, 103, -42, 41, 34, -114, 99, -32, 105, -59, 127, 45, 108, 74, -93,
        105, 33, 12, -5, -20, 17, -21, -119, -127, -115, 27, -122, 26, -67,
        109, -125, 16, 91, -70, 109};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.pow(exp);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", -1, result.signum());
  }

  /**
   * Exponentiation of a negative number to zero exponent.
   */
  public void testPowNegativeNumToZeroExp() {
    byte aBytes[] = {50, -26, 90, 69, 120, 32, 63, -103, -14, 35};
    int aSign = -1;
    int exp = 0;
    byte rBytes[] = {1};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.pow(exp);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Exponentiation of a positive number.
   */
  public void testPowPositiveNum() {
    byte aBytes[] = {50, -26, 90, 69, 120, 32, 63, -103, -14, 35};
    int aSign = 1;
    int exp = 5;
    byte rBytes[] = {
        20, 93, 41, 14, 126, -114, 49, 87, -116, 34, -4, -60, 91, -112, 74,
        -104, 41, -42, -35, 113, -100, 31, -106, 58, -128, -46, -109, -75, 92,
        -106, -34, -13, 4, 19, -18, 20, 118, 126, 114, -28, 121, -27, 66, -110,
        124, -17, -92, 69, -109};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.pow(exp);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }

  /**
   * Exponentiation of a negative number to zero exponent.
   */
  public void testPowPositiveNumToZeroExp() {
    byte aBytes[] = {50, -26, 90, 69, 120, 32, 63, -103, -14, 35};
    int aSign = 1;
    int exp = 0;
    byte rBytes[] = {1};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger result = aNumber.pow(exp);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals("incorrect sign", 1, result.signum());
  }
}