java.math.BigInteger.shiftLeft()方法的使用及代码示例

x33g5p2x  于2022-01-16 转载在 其他  
字(10.4k)|赞(0)|评价(0)|浏览(266)

本文整理了Java中java.math.BigInteger.shiftLeft()方法的一些代码示例，展示了BigInteger.shiftLeft()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。BigInteger.shiftLeft()方法的具体详情如下：
包路径：java.math.BigInteger
类名称：BigInteger
方法名：shiftLeft

BigInteger.shiftLeft介绍

[英]Returns a BigInteger whose value is this << n. The result is equivalent to this * pow(2, n) if n >= 0. The shift distance may be negative which means that this is shifted right. The result then corresponds to floor(this / pow(2, -n)).

Implementation Note: Usage of this method on negative values is not recommended as the current implementation is not efficient.
[中]返回一个BigInteger，其值为this<<n。如果n>=0，则结果等于this*pow（2，n）。换档距离可能为负数，这意味着它向右换档。然后，结果对应于地板（该/pow（2，-n））。
实施说明：不建议对负值使用此方法，因为当前的实施效率不高。

代码示例

代码示例来源：origin: zendesk/maxwell

private BigInteger bytesToBigInteger(byte[] bytes) {
  BigInteger res = BigInteger.ZERO;
  for (int i = 0; i < bytes.length; i++) {
    res = res.add(BigInteger.valueOf(bytes[i] & 0xFF).shiftLeft(i * 8));
  }
  return res;
}

代码示例来源：origin: org.apache.poi/poi

public ExpandedDouble(long rawBits) {
  int biasedExp = (int) (rawBits >> 52);
  if (biasedExp == 0) {
    // sub-normal numbers
    BigInteger frac = BigInteger.valueOf(rawBits).and(BI_FRAC_MASK);
    int expAdj = 64 - frac.bitLength();
    _significand = frac.shiftLeft(expAdj);
    _binaryExponent = (biasedExp & 0x07FF) - 1023 - expAdj;
  } else {
    _significand = getFrac(rawBits);
    _binaryExponent = (biasedExp & 0x07FF) - 1023;
  }
}

代码示例来源：origin: io.netty/netty

private static BigInteger ipv6CidrMaskToMask(int cidrMask) {
  return BigInteger.ONE.shiftLeft(128 - cidrMask).subtract(BigInteger.ONE).not();
}

代码示例来源：origin: deeplearning4j/nd4j

Bernoulli b = new Bernoulli();
BigInteger fourn = BigInteger.valueOf(4);
BigInteger fac = BigInteger.valueOf(2);
for (int i = 2;; i++) {
  Rational f = b.at(2 * i).abs();
  fourn = fourn.shiftLeft(2);
  fac = fac.multiply(BigInteger.valueOf(2 * i)).multiply(BigInteger.valueOf(2 * i - 1));
  f = f.multiply(fourn).multiply(fourn.subtract(BigInteger.ONE)).divide(fac);
  xpowi = multiplyRound(xpowi, xhighprSq);
  BigDecimal c = multiplyRound(xpowi, f);

代码示例来源：origin: stackoverflow.com

this(BigInteger.valueOf(numerator), BigInteger.valueOf(denominator));
this(BigInteger.valueOf(numerator), BigInteger.ONE, true);
 tmpNumerator = tmpNumerator.multiply(BigInteger.ONE.shiftLeft(exponent));
else
 tmpDenominator = tmpDenominator.multiply(BigInteger.ONE.shiftLeft(-exponent));
return new BigFraction(numerator.multiply(f.denominator).add(denominator.multiply(f.numerator)),
            denominator.multiply(f.denominator));
return new BigFraction(numerator.add(denominator.multiply(b)),
            denominator, true);
 throw new IllegalArgumentException("Null argument");
return new BigFraction(numerator.multiply(f.denominator).subtract(denominator.multiply(f.numerator)),
            denominator.multiply(f.denominator));
 throw new IllegalArgumentException("Null argument");
return new BigFraction(denominator.subtract(numerator), denominator, true);
  unscaled = unscaled.shiftLeft(fives - twos); //x * 2^n === x << n
 else if (fives < twos)
  unscaled = unscaled.multiply(FIVE.pow(twos - fives));

代码示例来源：origin: google/guava

sqrt0 = sqrtApproxWithDoubles(x.shiftRight(shift)).shiftLeft(shift >> 1);
BigInteger sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
if (sqrt0.equals(sqrt1)) {
 return sqrt0;
 sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
} while (sqrt1.compareTo(sqrt0) < 0);
return sqrt0;

代码示例来源：origin: robovm/robovm

mantissa = mantissa.shiftLeft(k);
  exponent -= k;
mantissa = quotAndRem[0].shiftLeft(2).add(
    BigInteger.valueOf((compRem * (compRem + 3)) / 2 + 1));
exponent -= 2;

代码示例来源：origin: google/guava

@GwtIncompatible // TODO
public void testSqrtHalfDown() {
 for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
  BigInteger result = BigIntegerMath.sqrt(x, HALF_DOWN);
  BigInteger plusHalfSquared = result.pow(2).add(result).shiftLeft(2).add(ONE);
  BigInteger x4 = x.shiftLeft(2);
  // sqrt(x) <= result + 0.5, so 4 * x <= (result + 0.5)^2 * 4
  // (result + 0.5)^2 * 4 = (result^2 + result)*4 + 1
  assertTrue(x4.compareTo(plusHalfSquared) <= 0);
  BigInteger minusHalfSquared = result.pow(2).subtract(result).shiftLeft(2).add(ONE);
  // sqrt(x) > result - 0.5, so 4 * x > (result - 0.5)^2 * 4
  // (result - 0.5)^2 * 4 = (result^2 - result)*4 + 1
  assertTrue(result.equals(ZERO) || x4.compareTo(minusHalfSquared) > 0);
 }
}

代码示例来源：origin: apache/hive

/**
 * Convert this object to {@link BigInteger}. Do not use this method in a
 * performance sensitive place.
 *
 * @return BigInteger to represent this object
 */
public BigInteger toBigIntegerSlow() {
 BigInteger bigInt = BigInteger.valueOf(v[3] & SqlMathUtil.LONG_MASK);
 bigInt = bigInt.shiftLeft(32);
 bigInt = bigInt.add(BigInteger.valueOf(v[2] & SqlMathUtil.LONG_MASK));
 bigInt = bigInt.shiftLeft(32);
 bigInt = bigInt.add(BigInteger.valueOf(v[1] & SqlMathUtil.LONG_MASK));
 bigInt = bigInt.shiftLeft(32);
 bigInt = bigInt.add(BigInteger.valueOf(v[0] & SqlMathUtil.LONG_MASK));
 return bigInt;
}

代码示例来源：origin: plutext/docx4j

public ExpandedDouble(long rawBits) {
  int biasedExp = (int) (rawBits >> 52);
  if (biasedExp == 0) {
    // sub-normal numbers
    BigInteger frac = BigInteger.valueOf(rawBits).and(BI_FRAC_MASK);
    int expAdj = 64 - frac.bitLength();
    _significand = frac.shiftLeft(expAdj);
    _binaryExponent = (biasedExp & 0x07FF) - 1023 - expAdj;
  } else {
    BigInteger frac = getFrac(rawBits);
    _significand = frac;
    _binaryExponent = (biasedExp & 0x07FF) - 1023;
  }
}

代码示例来源：origin: de.dfki.cos.basys.common/de.dfki.cos.basys.common.jrosbridge

/**
 * Convert the given value in unsigned 64-bit representation into its actual
 * value. That is, all return values of this function will be positive.
 * 
 * @param value
 *            The unsigned 64-bit value to convert.
 * @return The value of the given 64-bit unsigned value.
 */
public static BigInteger fromUInt64(long value) {
  return BigInteger.valueOf(value).and(
      BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE));
}

代码示例来源：origin: prestodb/presto

@Test
public void testRescale()
{
  assertEquals(rescale(unscaledDecimal(10), 0), unscaledDecimal(10L));
  assertEquals(rescale(unscaledDecimal(10), -20), unscaledDecimal(0L));
  assertEquals(rescale(unscaledDecimal(15), -1), unscaledDecimal(2));
  assertEquals(rescale(unscaledDecimal(1050), -3), unscaledDecimal(1));
  assertEquals(rescale(unscaledDecimal(15), 1), unscaledDecimal(150));
  assertEquals(rescale(unscaledDecimal(-14), -1), unscaledDecimal(-1));
  assertEquals(rescale(unscaledDecimal(-14), 1), unscaledDecimal(-140));
  assertEquals(rescale(unscaledDecimal(0), 1), unscaledDecimal(0));
  assertEquals(rescale(unscaledDecimal(5), -1), unscaledDecimal(1));
  assertEquals(rescale(unscaledDecimal(10), 10), unscaledDecimal(100000000000L));
  assertEquals(rescale(unscaledDecimal("150000000000000000000"), -20), unscaledDecimal(2));
  assertEquals(rescale(unscaledDecimal("-140000000000000000000"), -20), unscaledDecimal(-1));
  assertEquals(rescale(unscaledDecimal("50000000000000000000"), -20), unscaledDecimal(1));
  assertEquals(rescale(unscaledDecimal("150500000000000000000"), -18), unscaledDecimal(151));
  assertEquals(rescale(unscaledDecimal("-140000000000000000000"), -18), unscaledDecimal(-140));
  assertEquals(rescale(unscaledDecimal(BigInteger.ONE.shiftLeft(63)), -18), unscaledDecimal(9L));
  assertEquals(rescale(unscaledDecimal(BigInteger.ONE.shiftLeft(62)), -18), unscaledDecimal(5L));
  assertEquals(rescale(unscaledDecimal(BigInteger.ONE.shiftLeft(62)), -19), unscaledDecimal(0L));
  assertEquals(rescale(MAX_DECIMAL, -1), unscaledDecimal(MAX_DECIMAL_UNSCALED_VALUE.divide(BigInteger.TEN).add(BigInteger.ONE)));
  assertEquals(rescale(MIN_DECIMAL, -10), unscaledDecimal(MIN_DECIMAL_UNSCALED_VALUE.divide(BigInteger.valueOf(10000000000L)).subtract(BigInteger.ONE)));
  assertEquals(rescale(unscaledDecimal(1), 37), unscaledDecimal("10000000000000000000000000000000000000"));
  assertEquals(rescale(unscaledDecimal(-1), 37), unscaledDecimal("-10000000000000000000000000000000000000"));
  assertEquals(rescale(unscaledDecimal("10000000000000000000000000000000000000"), -37), unscaledDecimal(1));
}

代码示例来源：origin: prestodb/presto

private static void writeBigInteger(OutputStream output, BigInteger value)
      throws IOException
  {
    // encode the signed number as a positive integer
    value = value.shiftLeft(1);
    int sign = value.signum();
    if (sign < 0) {
      value = value.negate();
      value = value.subtract(ONE);
    }
    int length = value.bitLength();
    while (true) {
      long lowBits = value.longValue() & 0x7fffffffffffffffL;
      length -= 63;
      // write out the next 63 bits worth of data
      for (int i = 0; i < 9; ++i) {
        // if this is the last byte, leave the high bit off
        if (length <= 0 && (lowBits & ~0x7f) == 0) {
          output.write((byte) lowBits);
          return;
        }
        else {
          output.write((byte) (0x80 | (lowBits & 0x7f)));
          lowBits >>>= 7;
        }
      }
      value = value.shiftRight(63);
    }
  }
}

代码示例来源：origin: prestodb/presto

sqrt0 = sqrtApproxWithDoubles(x.shiftRight(shift)).shiftLeft(shift >> 1);
BigInteger sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
if (sqrt0.equals(sqrt1)) {
 return sqrt0;
 sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
} while (sqrt1.compareTo(sqrt0) < 0);
return sqrt0;

代码示例来源：origin: google/guava

@GwtIncompatible // TODO
public void testSqrtHalfUp() {
 for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
  BigInteger result = BigIntegerMath.sqrt(x, HALF_UP);
  BigInteger plusHalfSquared = result.pow(2).add(result).shiftLeft(2).add(ONE);
  BigInteger x4 = x.shiftLeft(2);
  // sqrt(x) < result + 0.5, so 4 * x < (result + 0.5)^2 * 4
  // (result + 0.5)^2 * 4 = (result^2 + result)*4 + 1
  assertTrue(x4.compareTo(plusHalfSquared) < 0);
  BigInteger minusHalfSquared = result.pow(2).subtract(result).shiftLeft(2).add(ONE);
  // sqrt(x) > result - 0.5, so 4 * x > (result - 0.5)^2 * 4
  // (result - 0.5)^2 * 4 = (result^2 - result)*4 + 1
  assertTrue(result.equals(ZERO) || x4.compareTo(minusHalfSquared) >= 0);
 }
}

代码示例来源：origin: stackoverflow.com

/** the constant 2^64 */
private static final BigInteger TWO_64 = BigInteger.ONE.shiftLeft(64);

public String asUnsignedDecimalString(long l) {
  BigInteger b = BigInteger.valueOf(l);
  if(b.signum() < 0) {
   b = b.add(TWO_64);
  }
  return b.toString();
}

代码示例来源：origin: plutext/docx4j

private static BigInteger getFrac(long rawBits) {
  return BigInteger.valueOf(rawBits).and(BI_FRAC_MASK).or(BI_IMPLIED_FRAC_MSB).shiftLeft(11);
}

代码示例来源：origin: rctoris/jrosbridge

/**
 * Convert the given value in unsigned 64-bit representation into its actual
 * value. That is, all return values of this function will be positive.
 * 
 * @param value
 *            The unsigned 64-bit value to convert.
 * @return The value of the given 64-bit unsigned value.
 */
public static BigInteger fromUInt64(long value) {
  return BigInteger.valueOf(value).and(
      BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE));
}

代码示例来源：origin: i2p/i2p.i2p

@Override
public synchronized void setField(Field f) {
  super.setField(f);
  mask = BigInteger.ONE.shiftLeft(f.getb()-1).subtract(BigInteger.ONE);
}

代码示例来源：origin: google/j2objc

sqrt0 = sqrtApproxWithDoubles(x.shiftRight(shift)).shiftLeft(shift >> 1);
BigInteger sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
if (sqrt0.equals(sqrt1)) {
 return sqrt0;
 sqrt1 = sqrt0.add(x.divide(sqrt0)).shiftRight(1);
} while (sqrt1.compareTo(sqrt0) < 0);
return sqrt0;

内容来源于网络，如有侵权，请联系作者删除！

BigInteger

相关文章

    查看更多

    热门标签

    更多
    JavaquerypythonNode开发语言requestUtil数据库Table后端算法LoggerMessageElementParser

    最新文章

    更多

    BigInteger类方法

    • 蜀ICP备2022004421号-2 NULL123 https://www.null123.com © All rights reserved
    • 本站内容来源互联网,如果侵犯您的权益请联系我们删除, 联系方式：448109455@qq.com