user/test/com/google/gwt/emultest/java/math/BigIntegerSubtractTest.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: subtract
 */
public class BigIntegerSubtractTest extends EmulTestBase {
  /**
   * Subtract two positive numbers of the same length. The first is greater.
   */
  public void testCase1() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {9, 18, 27, 36, 45, 54, 63, 9, 18, 27};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two positive numbers of different length. The second is longer.
   */
  public void testCase10() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {-2, -3, -4, -4, 5, 14, 23, 39, 48, 57, 66, 5, 14, 23};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two numbers of different length and different signs. The first is
   * positive. The first is greater in absolute value.
   */
  public void testCase11() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {1, 2, 3, 4, 15, 26, 37, 41, 52, 63, 74, 15, 26, 37};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * positive. The second is greater in absolute value.
   */
  public void testCase12() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {1, 2, 3, 4, 15, 26, 37, 41, 52, 63, 74, 15, 26, 37};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two numbers of different length and different signs. The first is
   * negative. The first is longer.
   */
  public void testCase13() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = -1;
    int bSign = 1;
    byte rBytes[] = {
        -2, -3, -4, -5, -16, -27, -38, -42, -53, -64, -75, -16, -27, -37};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * negative. The second is longer.
   */
  public void testCase14() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = -1;
    int bSign = 1;
    byte rBytes[] = {
        -2, -3, -4, -5, -16, -27, -38, -42, -53, -64, -75, -16, -27, -37};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two negative numbers of different length. The first is longer.
   */
  public void testCase15() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = -1;
    int bSign = -1;
    byte rBytes[] = {-2, -3, -4, -4, 5, 14, 23, 39, 48, 57, 66, 5, 14, 23};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two negative numbers of different length. The second is longer.
   */
  public void testCase16() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    int aSign = -1;
    int bSign = -1;
    byte rBytes[] = {1, 2, 3, 3, -6, -15, -24, -40, -49, -58, -67, -6, -15, -23};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two positive equal in absolute value numbers.
   */
  public void testCase17() {
    byte aBytes[] = {-120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte bBytes[] = {-120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte rBytes[] = {0};
    int aSign = 1;
    int bSign = 1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(0, result.signum());
  }

  /**
   * Subtract zero from a number. The number is positive.
   */
  public void testCase18() {
    byte aBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte bBytes[] = {0};
    byte rBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    int aSign = 1;
    int bSign = 0;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract a number from zero. The number is negative.
   */
  public void testCase19() {
    byte aBytes[] = {0};
    byte bBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte rBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    int aSign = 0;
    int bSign = -1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two positive numbers of the same length. The second is greater.
   */
  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[] = {-10, -19, -28, -37, -46, -55, -64, -10, -19, -27};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract zero from zero.
   */
  public void testCase20() {
    byte aBytes[] = {0};
    byte bBytes[] = {0};
    byte rBytes[] = {0};
    int aSign = 0;
    int bSign = 0;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(0, result.signum());
  }

  /**
   * Subtract ZERO from a number. The number is positive.
   */
  public void testCase21() {
    byte aBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte rBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    int aSign = 1;
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = BigInteger.ZERO;
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract a number from ZERO. The number is negative.
   */
  public void testCase22() {
    byte bBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    byte rBytes[] = {120, 34, 78, -23, -111, 45, 127, 23, 45, -3};
    int bSign = -1;
    BigInteger aNumber = BigInteger.ZERO;
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract ZERO from ZERO.
   */
  public void testCase23() {
    byte rBytes[] = {0};
    BigInteger aNumber = BigInteger.ZERO;
    BigInteger bNumber = BigInteger.ZERO;
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(0, result.signum());
  }

  /**
   * Subtract ONE from ONE.
   */
  public void testCase24() {
    byte rBytes[] = {0};
    BigInteger aNumber = BigInteger.ONE;
    BigInteger bNumber = BigInteger.ONE;
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(0, result.signum());
  }

  /**
   * Subtract two numbers so that borrow is 1.
   */
  public void testCase25() {
    byte aBytes[] = {-1, -1, -1, -1, -1, -1, -1, -1};
    byte bBytes[] = {-128, -128, -128, -128, -128, -128, -128, -128, -128};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {-128, 127, 127, 127, 127, 127, 127, 127, 127};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * positive. The first is greater in absolute value.
   */
  public void testCase3() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    int aSign = 1;
    int bSign = -1;
    byte rBytes[] = {11, 22, 33, 44, 55, 66, 77, 11, 22, 33};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * positive. The second is greater in absolute value.
   */
  public void testCase4() {
    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, 22, 33, 44, 55, 66, 77, 11, 22, 33};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two negative numbers of the same length. The first is greater in
   * absolute value.
   */
  public void testCase5() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    int aSign = -1;
    int bSign = -1;
    byte rBytes[] = {-10, -19, -28, -37, -46, -55, -64, -10, -19, -27};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two negative numbers of the same length. The second is greater in
   * absolute value.
   */
  public void testCase6() {
    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[] = {9, 18, 27, 36, 45, 54, 63, 9, 18, 27};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * negative. The first is greater in absolute value.
   */
  public void testCase7() {
    byte aBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    byte bBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3};
    int aSign = -1;
    int bSign = 1;
    byte rBytes[] = {-12, -23, -34, -45, -56, -67, -78, -12, -23, -33};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two numbers of the same length and different signs. The first is
   * negative. The second is greater in absolute value.
   */
  public void testCase8() {
    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[] = {-12, -23, -34, -45, -56, -67, -78, -12, -23, -33};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(-1, result.signum());
  }

  /**
   * Subtract two positive numbers of different length. The first is longer.
   */
  public void testCase9() {
    byte aBytes[] = {1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7};
    byte bBytes[] = {10, 20, 30, 40, 50, 60, 70, 10, 20, 30};
    int aSign = 1;
    int bSign = 1;
    byte rBytes[] = {1, 2, 3, 3, -6, -15, -24, -40, -49, -58, -67, -6, -15, -23};
    BigInteger aNumber = new BigInteger(aSign, aBytes);
    BigInteger bNumber = new BigInteger(bSign, bBytes);
    BigInteger result = aNumber.subtract(bNumber);
    byte resBytes[] = new byte[rBytes.length];
    resBytes = result.toByteArray();
    for (int i = 0; i < resBytes.length; i++) {
      assertTrue(resBytes[i] == rBytes[i]);
    }
    assertEquals(1, result.signum());
  }
}