java.math
Class BigInteger
java.lang.Object
|
+--java.lang.Number
|
+--java.math.BigInteger
- All Implemented Interfaces:
- Comparable, Serializable
- public class BigInteger
- extends Number
- implements Comparable
Safe:
- See Also:
- Serialized Form
Field Summary
private int
bitCount
The bitCount of this BigInteger, as returned by bitCount(), or -1
(either value is acceptable).
private int
bitLength
The bitLength of this BigInteger, as returned by bitLength(), or -1
(either value is acceptable).
private int
firstNonzeroByteNum
The index of the lowest-order byte in the magnitude of this BigInteger
that contains a nonzero byte, or -2 (either value is acceptable).
private int
firstNonzeroIntNum
The index of the lowest-order int in the magnitude of this BigInteger
that contains a nonzero int, or -2 (either value is acceptable).
private static long
LONG_MASK
This mask is used to obtain the value of an int as if it were unsigned.
private int
lowestSetBit
The lowest set bit of this BigInteger, as returned by getLowestSetBit(),
or -2 (either value is acceptable).
(package private) int[]
mag
The magnitude of this BigInteger, in
big-endian order: the
zeroth element of this array is the most-significant int of the
magnitude.
private static int
MAX_CONSTANT
Initialize static constant array when class is loaded.
(package private) int
signum
The signum of this BigInteger: -1 for negative, 0 for zero, or
1 for positive.
Constructor Summary
BigInteger(byte[] val)
Enabled: Translates a byte array containing the two's-complement binary
representation of a BigInteger into a BigInteger.
private
BigInteger(byte[] magnitude,
int signum)
This private constructor is for internal use and assumes that its
arguments are correct.
private
BigInteger(int[] val)
This private constructor translates an int array containing the
two's-complement binary representation of a BigInteger into a
BigInteger.
private
BigInteger(int[] magnitude,
int signum)
This private constructor differs from its public cousin
with the arguments reversed in two ways: it assumes that its
arguments are correct, and it doesn't copy the magnitude array.
BigInteger(int signum,
byte[] magnitude)
Enabled: Translates the sign-magnitude representation of a BigInteger into a
BigInteger.
private
BigInteger(int signum,
int[] magnitude)
A constructor for internal use that translates the sign-magnitude
representation of a BigInteger into a BigInteger.
BigInteger(int bitLength,
int certainty,
Random rnd)
Enabled: Constructs a randomly generated positive BigInteger that is probably
prime, with the specified bitLength.
BigInteger(int numBits,
Random rnd)
Enabled: Constructs a randomly generated BigInteger, uniformly distributed over
the range
0 to
(2numBits - 1), inclusive.
private
BigInteger(long val)
Constructs a BigInteger with the specified value, which may not be zero.
(package private)
BigInteger(MutableBigInteger val,
int sign)
This private constructor is for internal use in converting
from a MutableBigInteger object into a BigInteger.
BigInteger(String val)
Enabled: Translates the decimal String representation of a BigInteger into a
BigInteger.
BigInteger(String val,
int radix)
Enabled: Translates the String representation of a BigInteger in the specified
radix into a BigInteger.
Method Summary
boolean
aboveZero()
Added: Used in the expansion of E's ">" operator
BigInteger
abs()
Enabled: Returns a BigInteger whose value is the absolute value of this
BigInteger.
private static int[]
add(int[] x,
int[] y)
Adds the contents of the int arrays x and y.
(package private) static int
addOne(int[] a,
int offset,
int mlen,
int carry)
Add one word to the number a mlen words into a.
double
approxDivide(double arg)
Added: Always gives back a Double
This corresponds to the Java floating-point "/" operator
and the E "/" operator.
char
asChar()
Added: Returns the Unicode character with this character code.
double
asFloat64()
Added: Returns the "best" IEEE double precision floating point equivalent to
this number.
boolean
atLeastZero()
Added: Used in the expansion of E's ">=" operator
boolean
atMostZero()
Added: Used in the expansion of E's "<=" operator
boolean
belowZero()
Added: Used in the expansion of E's "<" operator
(package private) static int
bitCnt(int val)
int
bitCount()
Enabled: Returns the number of bits in the two's complement representation
of this BigInteger that differ from its sign bit.
(package private) static int
bitLen(int w)
bitLen(val) is the number of bits in val.
int
bitLength()
Enabled: Returns the number of bits in the minimal two's-complement
representation of this BigInteger,
excluding a sign bit.
private static int
bitLength(int[] val,
int len)
Calculate bitlength of contents of the first len elements an int array,
assuming there are no leading zero ints.
BigInteger
ceil()
Added: Defined both here and in DoubleSugar, so you can use this to
get a ceil'ed integer no matter what kind of number you start
with.
BigInteger
clearBit(int n)
Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit cleared.
int
compareTo(BigInteger val)
Suppressed: Compares this BigInteger with the specified BigInteger.
int
compareTo(Object o)
Enabled: Compares this BigInteger with the specified Object.
int
compareTo(Object o)
Added: Overrides the inherited 'compareTo' to coerce 'o' to a BigInteger
double
doubleValue()
Enabled: Converts this BigInteger to a
double.
boolean
equals(Object x)
Suppressed: Compares this BigInteger with the specified Object for equality.
private int
firstNonzeroIntNum()
Returns the index of the int that contains the first nonzero int in the
little-endian binary representation of the magnitude (int 0 is the
least significant).
BigInteger
flipBit(int n)
Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit flipped.
float
floatValue()
Enabled: Converts this BigInteger to a
float.
BigInteger
floor()
Added: Defined both here and in DoubleSugar, so you can use this to
get a floor'ed integer no matter what kind of number you start
with.
BigInteger
gcd(BigInteger val)
Enabled: Returns a BigInteger whose value is the greatest common divisor of
abs(this) and
abs(val).
private int
getInt(int n)
Returns the specified int of the little-endian two's complement
representation (int 0 is the least significant).
int
getLowestSetBit()
Enabled: Returns the index of the rightmost (lowest-order) one bit in this
BigInteger (the number of zero bits to the right of the rightmost
one bit).
int
hashCode()
Suppressed: Returns the hash code for this BigInteger.
private int
intLength()
Returns the length of the two's complement representation in ints,
including space for at least one sign bit.
int
intValue()
Enabled: Converts this BigInteger to an
int.
boolean
isNaN()
Added: All integers are numbers, so this is always false
boolean
isProbablePrime(int certainty)
Suppressed: Returns
true if this BigInteger is probably prime,
false if it's definitely composite.
boolean
isZero()
Added: Used for arithmetic equality
private static BigInteger
largePrime(int bitLength,
int certainty,
Random rnd)
Find a random number of the specified bitLength that is probably prime.
private static int[]
leftShift(int[] a,
int len,
int n)
Left shift int array a up to len by n bits.
long
longValue()
Enabled: Converts this BigInteger to a
long.
private static int[]
makePositive(byte[] a)
Takes an array a representing a negative 2's-complement number and
returns the minimal (no leading zero bytes) unsigned whose value is -a.
private static int[]
makePositive(int[] a)
Takes an array a representing a negative 2's-complement number and
returns the minimal (no leading zero ints) unsigned whose value is -a.
private BigInteger
mod2(int p)
Returns a BigInteger whose value is this mod(2**p).
private static int[]
montReduce(int[] n,
int[] mod,
int mlen,
int inv)
Montgomery reduce n, modulo mod.
(package private) static int
mulAdd(int[] out,
int[] in,
int offset,
int len,
int k)
Multiply an array by one word k and add to result, return the carry
private int[]
multiplyToLen(int[] x,
int xlen,
int[] y,
int ylen,
int[] z)
Multiplies int arrays x and y to the specified lengths and places
the result into z.
BigInteger
not()
Enabled: Returns a BigInteger whose value is
(~this).
private int
parseInt(char[] source,
int start,
int end)
private boolean
passesLucasLehmer()
Returns true iff this BigInteger is a Lucas-Lehmer probable prime.
private boolean
passesMillerRabin(int iterations)
Returns true iff this BigInteger passes the specified number of
Miller-Rabin tests.
BigInteger
pow(int exponent)
Enabled: Returns a BigInteger whose value is
(thisexponent).
(package private) boolean
primeToCertainty(int certainty)
Returns
true if this BigInteger is probably prime,
false if it's definitely composite.
static BigInteger
probablePrime(int bitLength,
Random rnd)
Suppressed: Returns a positive BigInteger that is probably prime, with the
specified bitLength.
BigInteger
round()
Added: Defined both here and in DoubleSugar, so you can use this to
get round'ed integer no matter what kind of number you start
with.
BigInteger
setBit(int n)
Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit set.
int
signum()
Enabled: Returns the signum function of this BigInteger.
private static BigInteger
smallPrime(int bitLength,
int certainty,
Random rnd)
Find a random number of the specified bitLength that is probably prime.
private static int[]
squareToLen(int[] x,
int len,
int[] z)
Squares the contents of the int array x.
private static int[]
stripLeadingZeroBytes(byte[] a)
Returns a copy of the input array stripped of any leading zero bytes.
private static int[]
stripLeadingZeroInts(int[] val)
Returns a copy of the input array stripped of any leading zero bytes.
private static int
subN(int[] a,
int[] b,
int len)
Subtracts two numbers of same length, returning borrow.
private static int[]
subtract(int[] big,
int[] little)
Subtracts the contents of the second int arrays (little) from the
first (big).
boolean
testBit(int n)
Enabled: Returns
true if and only if the designated bit is set.
byte[]
toByteArray()
Enabled: Returns a byte array containing the two's-complement
representation of this BigInteger.
String
toString()
Suppressed: Returns the decimal String representation of this BigInteger.
String
toString(int radix)
Enabled: Returns the String representation of this BigInteger in the
given radix.
String
toString64()
Added: Convert an integer to a base 64 string, with an optional leading minus
sign.
BigInteger
truncate()
Added: Defined both here and in DoubleSugar, so you can use this to
get truncate'd integer no matter what kind of number you start
with.
private static BigInteger
valueOf(int[] val)
Returns a BigInteger with the given two's complement representation.
static BigInteger
valueOf(long val)
Enabled: Returns a BigInteger whose value is equal to that of the
specified
long.
Methods inherited from class java.lang.Number
Methods inherited from class java.lang.Object
Field Detail
signum
int signum
- The signum of this BigInteger: -1 for negative, 0 for zero, or
1 for positive. Note that the BigInteger zero must have
a signum of 0. This is necessary to ensures that there is exactly one
representation for each BigInteger value.
mag
int[] mag
- The magnitude of this BigInteger, in big-endian order: the
zeroth element of this array is the most-significant int of the
magnitude. The magnitude must be "minimal" in that the most-significant
int (mag[0]) must be non-zero. This is necessary to
ensure that there is exactly one representation for each BigInteger
value. Note that this implies that the BigInteger zero has a
zero-length mag array.
bitCount
private int bitCount
- The bitCount of this BigInteger, as returned by bitCount(), or -1
(either value is acceptable).
- See Also:
bitCount
bitLength
private int bitLength
- The bitLength of this BigInteger, as returned by bitLength(), or -1
(either value is acceptable).
- See Also:
bitLength
lowestSetBit
private int lowestSetBit
- The lowest set bit of this BigInteger, as returned by getLowestSetBit(),
or -2 (either value is acceptable).
- See Also:
getLowestSetBit()
firstNonzeroByteNum
private int firstNonzeroByteNum
- The index of the lowest-order byte in the magnitude of this BigInteger
that contains a nonzero byte, or -2 (either value is acceptable). The
least significant byte has int-number 0, the next byte in order of
increasing significance has byte-number 1, and so forth.
firstNonzeroIntNum
private int firstNonzeroIntNum
- The index of the lowest-order int in the magnitude of this BigInteger
that contains a nonzero int, or -2 (either value is acceptable). The
least significant int has int-number 0, the next int in order of
increasing significance has int-number 1, and so forth.
LONG_MASK
private static final long LONG_MASK
- This mask is used to obtain the value of an int as if it were unsigned.
bitsPerDigit
private static long[] bitsPerDigit
SMALL_PRIME_THRESHOLD
private static final int SMALL_PRIME_THRESHOLD
SMALL_PRIME_PRODUCT
private static final BigInteger SMALL_PRIME_PRODUCT
MAX_CONSTANT
private static final int MAX_CONSTANT
- Initialize static constant array when class is loaded.
posConst
private static BigInteger[] posConst
negConst
private static BigInteger[] negConst
ZERO
public static final BigInteger ZERO
- Enabled: The BigInteger constant zero.
- Since:
- 1.2
ONE
public static final BigInteger ONE
- Enabled: The BigInteger constant one.
- Since:
- 1.2
TWO
private static final BigInteger TWO
- The BigInteger constant two. (Not exported.)
bnExpModThreshTable
static int[] bnExpModThreshTable
trailingZeroTable
static final byte[] trailingZeroTable
zeros
private static String[] zeros
digitsPerLong
private static int[] digitsPerLong
longRadix
private static BigInteger[] longRadix
digitsPerInt
private static int[] digitsPerInt
intRadix
private static int[] intRadix
serialVersionUID
private static final long serialVersionUID
- use serialVersionUID from JDK 1.1. for interoperability
serialPersistentFields
private static final ObjectStreamField[] serialPersistentFields
- Serializable fields for BigInteger.
Constructor Detail
BigInteger
public BigInteger(byte[] val)
- Enabled: Translates a byte array containing the two's-complement binary
representation of a BigInteger into a BigInteger. The input array is
assumed to be in big-endian byte-order: the most significant
byte is in the zeroth element.
- Parameters:
val - big-endian two's-complement binary representation of
BigInteger.
- Throws:
NumberFormatException - val is zero bytes long.
BigInteger
private BigInteger(int[] val)
- This private constructor translates an int array containing the
two's-complement binary representation of a BigInteger into a
BigInteger. The input array is assumed to be in big-endian
int-order: the most significant int is in the zeroth element.
BigInteger
public BigInteger(int signum,
byte[] magnitude)
- Enabled: Translates the sign-magnitude representation of a BigInteger into a
BigInteger. The sign is represented as an integer signum value: -1 for
negative, 0 for zero, or 1 for positive. The magnitude is a byte array
in big-endian byte-order: the most significant byte is in the
zeroth element. A zero-length magnitude array is permissible, and will
result in in a BigInteger value of 0, whether signum is -1, 0 or 1.
- Parameters:
signum - signum of the number (-1 for negative, 0 for zero, 1
for positive).magnitude - big-endian binary representation of the magnitude of
the number.
- Throws:
NumberFormatException - signum is not one of the three
legal values (-1, 0, and 1), or signum is 0 and
magnitude contains one or more non-zero bytes.
BigInteger
private BigInteger(int signum,
int[] magnitude)
- A constructor for internal use that translates the sign-magnitude
representation of a BigInteger into a BigInteger. It checks the
arguments and copies the magnitude so this constructor would be
safe for external use.
BigInteger
public BigInteger(String val,
int radix)
- Enabled: Translates the String representation of a BigInteger in the specified
radix into a BigInteger. The String representation consists of an
optional minus sign followed by a sequence of one or more digits in the
specified radix. The character-to-digit mapping is provided by
Character.digit. The String may not contain any extraneous
characters (whitespace, for example).
- Parameters:
val - String representation of BigInteger.radix - radix to be used in interpreting val.
- Throws:
NumberFormatException - val is not a valid representation
of a BigInteger in the specified radix, or radix is
outside the range from Character.MIN_RADIX to
Character.MAX_RADIX, inclusive.- See Also:
Character.digit(char, int)
BigInteger
BigInteger(char[] val)
BigInteger
public BigInteger(String val)
- Enabled: Translates the decimal String representation of a BigInteger into a
BigInteger. The String representation consists of an optional minus
sign followed by a sequence of one or more decimal digits. The
character-to-digit mapping is provided by Character.digit.
The String may not contain any extraneous characters (whitespace, for
example).
- Parameters:
val - decimal String representation of BigInteger.
- Throws:
NumberFormatException - val is not a valid representation
of a BigInteger.- See Also:
Character.digit(char, int)
BigInteger
public BigInteger(int numBits,
Random rnd)
- Enabled: Constructs a randomly generated BigInteger, uniformly distributed over
the range 0 to (2numBits - 1), inclusive.
The uniformity of the distribution assumes that a fair source of random
bits is provided in rnd. Note that this constructor always
constructs a non-negative BigInteger.
- Parameters:
numBits - maximum bitLength of the new BigInteger.rnd - source of randomness to be used in computing the new
BigInteger.
- Throws:
IllegalArgumentException - numBits is negative.- See Also:
bitLength
BigInteger
public BigInteger(int bitLength,
int certainty,
Random rnd)
- Enabled: Constructs a randomly generated positive BigInteger that is probably
prime, with the specified bitLength.
It is recommended that the probablePrime
method be used in preference to this constructor unless there
is a compelling need to specify a certainty.
- Parameters:
bitLength - bitLength of the returned BigInteger.certainty - a measure of the uncertainty that the caller is
willing to tolerate. The probability that the new BigInteger
represents a prime number will exceed
(1 - 1/2certainty). The execution time of
this constructor is proportional to the value of this parameter.rnd - source of random bits used to select candidates to be
tested for primality.
- Throws:
ArithmeticException - bitLength < 2.- See Also:
bitLength
BigInteger
private BigInteger(int[] magnitude,
int signum)
- This private constructor differs from its public cousin
with the arguments reversed in two ways: it assumes that its
arguments are correct, and it doesn't copy the magnitude array.
BigInteger
private BigInteger(byte[] magnitude,
int signum)
- This private constructor is for internal use and assumes that its
arguments are correct.
BigInteger
BigInteger(MutableBigInteger val,
int sign)
- This private constructor is for internal use in converting
from a MutableBigInteger object into a BigInteger.
BigInteger
private BigInteger(long val)
- Constructs a BigInteger with the specified value, which may not be zero.
Method Detail
parseInt
private int parseInt(char[] source,
int start,
int end)
-
-
destructiveMulAdd
private static void destructiveMulAdd(int[] x,
int y,
int z)
-
-
randomBits
private static byte[] randomBits(int numBits,
Random rnd)
-
-
probablePrime
public static BigInteger probablePrime(int bitLength,
Random rnd)
- Suppressed: Returns a positive BigInteger that is probably prime, with the
specified bitLength. The probability that a BigInteger returned
by this method is composite does not exceed 2-100.
-
- Parameters:
bitLength - bitLength of the returned BigInteger.rnd - source of random bits used to select candidates to be
tested for primality.
- Returns:
- a BigInteger of bitLength bits that is probably prime
- Throws:
ArithmeticException - bitLength < 2.- See Also:
bitLength
smallPrime
private static BigInteger smallPrime(int bitLength,
int certainty,
Random rnd)
- Find a random number of the specified bitLength that is probably prime.
This method is used for smaller primes, its performance degrades on
larger bitlengths.
This method assumes bitLength> 1.
-
-
largePrime
private static BigInteger largePrime(int bitLength,
int certainty,
Random rnd)
- Find a random number of the specified bitLength that is probably prime.
This method is more appropriate for larger bitlengths since it uses
a sieve to eliminate most composites before using a more expensive
test.
-
-
primeToCertainty
boolean primeToCertainty(int certainty)
- Returns true if this BigInteger is probably prime,
false if it's definitely composite.
This method assumes bitLength> 2.
-
- Parameters:
certainty - a measure of the uncertainty that the caller is
willing to tolerate: if the call returns true
the probability that this BigInteger is prime exceeds
(1 - 1/2certainty). The execution time of
this method is proportional to the value of this parameter.
- Returns:
- true if this BigInteger is probably prime,
false if it's definitely composite.
passesLucasLehmer
private boolean passesLucasLehmer()
- Returns true iff this BigInteger is a Lucas-Lehmer probable prime.
The following assumptions are made:
This BigInteger is a positive, odd number.
-
-
jacobiSymbol
int jacobiSymbol(int p,
BigInteger n)
- Computes Jacobi(p,n).
Assumes n is positive, odd.
-
-
lucasLehmerSequence
private static BigInteger lucasLehmerSequence(int z,
BigInteger k,
BigInteger n)
-
-
passesMillerRabin
private boolean passesMillerRabin(int iterations)
- Returns true iff this BigInteger passes the specified number of
Miller-Rabin tests. This test is taken from the DSA spec (NIST FIPS
186-2).
The following assumptions are made:
This BigInteger is a positive, odd number greater than 2.
iterations<=50.
-
-
valueOf
public static BigInteger valueOf(long val)
- Enabled: Returns a BigInteger whose value is equal to that of the
specified
long. This "static factory method" is
provided in preference to a (long) constructor
because it allows for reuse of frequently used BigIntegers.
-
- Parameters:
val - value of the BigInteger to return.
- Returns:
- a BigInteger with the specified value.
valueOf
private static BigInteger valueOf(int[] val)
- Returns a BigInteger with the given two's complement representation.
Assumes that the input array will not be modified (the returned
BigInteger will reference the input array if feasible).
-
-
add
public BigInteger add(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this + val).
-
- Parameters:
val - value to be added to this BigInteger.
- Returns:
- this + val
add
private static int[] add(int[] x,
int[] y)
- Adds the contents of the int arrays x and y. This method allocates
a new int array to hold the answer and returns a reference to that
array.
-
-
subtract
public BigInteger subtract(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this - val).
-
- Parameters:
val - value to be subtracted from this BigInteger.
- Returns:
- this - val
subtract
private static int[] subtract(int[] big,
int[] little)
- Subtracts the contents of the second int arrays (little) from the
first (big). The first int array (big) must represent a larger number
than the second. This method allocates the space necessary to hold the
answer.
-
-
multiply
public BigInteger multiply(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this * val).
-
- Parameters:
val - value to be multiplied by this BigInteger.
- Returns:
- this * val
multiplyToLen
private int[] multiplyToLen(int[] x,
int xlen,
int[] y,
int ylen,
int[] z)
- Multiplies int arrays x and y to the specified lengths and places
the result into z.
-
-
square
private BigInteger square()
- Returns a BigInteger whose value is (this2).
-
- Returns:
- this2
squareToLen
private static final int[] squareToLen(int[] x,
int len,
int[] z)
- Squares the contents of the int array x. The result is placed into the
int array z. The contents of x are not changed.
-
-
divide
public BigInteger divide(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this / val).
-
- Parameters:
val - value by which this BigInteger is to be divided.
- Returns:
- this / val
- Throws:
ArithmeticException - val==0
divideAndRemainder
public BigInteger[] divideAndRemainder(BigInteger val)
- Enabled: Returns an array of two BigIntegers containing (this / val)
followed by (this % val).
-
- Parameters:
val - value by which this BigInteger is to be divided, and the
remainder computed.
- Returns:
- an array of two BigIntegers: the quotient (this / val)
is the initial element, and the remainder (this % val)
is the final element.
- Throws:
ArithmeticException - val==0
remainder
public BigInteger remainder(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this % val).
-
- Parameters:
val - value by which this BigInteger is to be divided, and the
remainder computed.
- Returns:
- this % val
- Throws:
ArithmeticException - val==0
pow
public BigInteger pow(int exponent)
- Enabled: Returns a BigInteger whose value is (thisexponent).
Note that exponent is an integer rather than a BigInteger.
-
- Parameters:
exponent - exponent to which this BigInteger is to be raised.
- Returns:
- thisexponent
- Throws:
ArithmeticException - exponent is negative. (This would
cause the operation to yield a non-integer value.)
gcd
public BigInteger gcd(BigInteger val)
- Enabled: Returns a BigInteger whose value is the greatest common divisor of
abs(this) and abs(val). Returns 0 if
this==0 && val==0.
-
- Parameters:
val - value with with the GCD is to be computed.
- Returns:
- GCD(abs(this), abs(val))
leftShift
private static int[] leftShift(int[] a,
int len,
int n)
- Left shift int array a up to len by n bits. Returns the array that
results from the shift since space may have to be reallocated.
-
-
primitiveRightShift
static void primitiveRightShift(int[] a,
int len,
int n)
-
-
primitiveLeftShift
static void primitiveLeftShift(int[] a,
int len,
int n)
-
-
bitLength
private static int bitLength(int[] val,
int len)
- Calculate bitlength of contents of the first len elements an int array,
assuming there are no leading zero ints.
-
-
abs
public BigInteger abs()
- Enabled: Returns a BigInteger whose value is the absolute value of this
BigInteger.
-
- Returns:
- abs(this)
negate
public BigInteger negate()
- Enabled: Returns a BigInteger whose value is (-this).
-
- Returns:
- -this
signum
public int signum()
- Enabled: Returns the signum function of this BigInteger.
-
- Returns:
- -1, 0 or 1 as the value of this BigInteger is negative, zero or
positive.
mod
public BigInteger mod(BigInteger m)
- Enabled: Returns a BigInteger whose value is (this mod m). This method
differs from remainder in that it always returns a
non-negative BigInteger.
-
- Parameters:
m - the modulus.
- Returns:
- this mod m
- Throws:
ArithmeticException - m <= 0- See Also:
remainder(java.math.BigInteger)
modPow
public BigInteger modPow(BigInteger exponent,
BigInteger m)
- Enabled: Returns a BigInteger whose value is
(thisexponent mod m). (Unlike pow, this
method permits negative exponents.)
-
- Parameters:
exponent - the exponent.m - the modulus.
- Returns:
- thisexponent mod m
- Throws:
ArithmeticException - m <= 0- See Also:
modInverse(java.math.BigInteger)
oddModPow
private BigInteger oddModPow(BigInteger y,
BigInteger z)
- Returns a BigInteger whose value is x to the power of y mod z.
Assumes: z is odd && x < z.
-
-
montReduce
private static int[] montReduce(int[] n,
int[] mod,
int mlen,
int inv)
- Montgomery reduce n, modulo mod. This reduces modulo mod and divides
by 2^(32*mlen). Adapted from Colin Plumb's C library.
-
-
intArrayCmpToLen
private static int intArrayCmpToLen(int[] arg1,
int[] arg2,
int len)
-
-
subN
private static int subN(int[] a,
int[] b,
int len)
- Subtracts two numbers of same length, returning borrow.
-
-
mulAdd
static int mulAdd(int[] out,
int[] in,
int offset,
int len,
int k)
- Multiply an array by one word k and add to result, return the carry
-
-
addOne
static int addOne(int[] a,
int offset,
int mlen,
int carry)
- Add one word to the number a mlen words into a. Return the resulting
carry.
-
-
modPow2
private BigInteger modPow2(BigInteger exponent,
int p)
- Returns a BigInteger whose value is (this ** exponent) mod (2**p)
-
-
mod2
private BigInteger mod2(int p)
- Returns a BigInteger whose value is this mod(2**p).
Assumes that this BigInteger >= 0 and p > 0.
-
-
modInverse
public BigInteger modInverse(BigInteger m)
- Enabled: Returns a BigInteger whose value is (this-1 mod m).
-
- Parameters:
m - the modulus.
- Returns:
- this-1 mod m.
- Throws:
ArithmeticException - m <= 0, or this BigInteger
has no multiplicative inverse mod m (that is, this BigInteger
is not relatively prime to m).
shiftLeft
public BigInteger shiftLeft(int n)
- Enabled: Returns a BigInteger whose value is (this << n).
The shift distance, n, may be negative, in which case
this method performs a right shift.
(Computes floor(this * 2n).)
-
- Parameters:
n - shift distance, in bits.
- Returns:
- this << n
- See Also:
shiftRight(int)
shiftRight
public BigInteger shiftRight(int n)
- Enabled: Returns a BigInteger whose value is (this >> n). Sign
extension is performed. The shift distance, n, may be
negative, in which case this method performs a left shift.
(Computes floor(this / 2n).)
-
- Parameters:
n - shift distance, in bits.
- Returns:
- this >> n
- See Also:
shiftLeft(int)
javaIncrement
int[] javaIncrement(int[] val)
-
-
and
public BigInteger and(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this & val). (This
method returns a negative BigInteger if and only if this and val are
both negative.)
-
- Parameters:
val - value to be AND'ed with this BigInteger.
- Returns:
- this & val
or
public BigInteger or(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this | val). (This method
returns a negative BigInteger if and only if either this or val is
negative.)
-
- Parameters:
val - value to be OR'ed with this BigInteger.
- Returns:
- this | val
xor
public BigInteger xor(BigInteger val)
- Enabled: Returns a BigInteger whose value is (this ^ val). (This method
returns a negative BigInteger if and only if exactly one of this and
val are negative.)
-
- Parameters:
val - value to be XOR'ed with this BigInteger.
- Returns:
- this ^ val
not
public BigInteger not()
- Enabled: Returns a BigInteger whose value is (~this). (This method
returns a negative value if and only if this BigInteger is
non-negative.)
-
- Returns:
- ~this
andNot
public BigInteger andNot(BigInteger val)
- Suppressed: Returns a BigInteger whose value is (this & ~val). This
method, which is equivalent to and(val.not()), is provided as
a convenience for masking operations. (This method returns a negative
BigInteger if and only if this is negative and val is
positive.)
-
- Parameters:
val - value to be complemented and AND'ed with this BigInteger.
- Returns:
- this & ~val
testBit
public boolean testBit(int n)
- Enabled: Returns true if and only if the designated bit is set.
(Computes ((this & (1<<n)) != 0).)
-
- Parameters:
n - index of bit to test.
- Returns:
- true if and only if the designated bit is set.
- Throws:
ArithmeticException - n is negative.
setBit
public BigInteger setBit(int n)
- Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit set. (Computes (this | (1<<n)).)
-
- Parameters:
n - index of bit to set.
- Returns:
- this | (1<<n)
- Throws:
ArithmeticException - n is negative.
clearBit
public BigInteger clearBit(int n)
- Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit cleared.
(Computes (this & ~(1<<n)).)
-
- Parameters:
n - index of bit to clear.
- Returns:
- this & ~(1<<n)
- Throws:
ArithmeticException - n is negative.
flipBit
public BigInteger flipBit(int n)
- Enabled: Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit flipped.
(Computes (this ^ (1<<n)).)
-
- Parameters:
n - index of bit to flip.
- Returns:
- this ^ (1<<n)
- Throws:
ArithmeticException - n is negative.
getLowestSetBit
public int getLowestSetBit()
- Enabled: Returns the index of the rightmost (lowest-order) one bit in this
BigInteger (the number of zero bits to the right of the rightmost
one bit). Returns -1 if this BigInteger contains no one bits.
(Computes (this==0? -1 : log2(this & -this)).)
-
- Returns:
- index of the rightmost one bit in this BigInteger.
bitLength
public int bitLength()
- Enabled: Returns the number of bits in the minimal two's-complement
representation of this BigInteger, excluding a sign bit.
For positive BigIntegers, this is equivalent to the number of bits in
the ordinary binary representation. (Computes
(ceil(log2(this < 0 ? -this : this+1))).)
-
- Returns:
- number of bits in the minimal two's-complement
representation of this BigInteger, excluding a sign bit.
bitLen
static int bitLen(int w)
- bitLen(val) is the number of bits in val.
-
-
bitCount
public int bitCount()
- Enabled: Returns the number of bits in the two's complement representation
of this BigInteger that differ from its sign bit. This method is
useful when implementing bit-vector style sets atop BigIntegers.
-
- Returns:
- number of bits in the two's complement representation
of this BigInteger that differ from its sign bit.
bitCnt
static int bitCnt(int val)
-
-
trailingZeroCnt
static int trailingZeroCnt(int val)
-
-
isProbablePrime
public boolean isProbablePrime(int certainty)
- Suppressed: Returns true if this BigInteger is probably prime,
false if it's definitely composite. If
certainty is <= 0, true is
returned.
-
- Parameters:
certainty - a measure of the uncertainty that the caller is
willing to tolerate: if the call returns true
the probability that this BigInteger is prime exceeds
(1 - 1/2certainty). The execution time of
this method is proportional to the value of this parameter.
- Returns:
- true if this BigInteger is probably prime,
false if it's definitely composite.
compareTo
public int compareTo(BigInteger val)
- Suppressed: Compares this BigInteger with the specified BigInteger. This method is
provided in preference to individual methods for each of the six
boolean comparison operators (<, ==, >, >=, !=, <=). The
suggested idiom for performing these comparisons is:
(x.compareTo(y) <op> 0),
where <op> is one of the six comparison operators.
-
- Parameters:
val - BigInteger to which this BigInteger is to be compared.
- Returns:
- -1, 0 or 1 as this BigInteger is numerically less than, equal
to, or greater than val.
compareTo
public int compareTo(Object o)
- Enabled: Compares this BigInteger with the specified Object. If the Object is a
BigInteger, this method behaves like compareTo(BigInteger).
Otherwise, it throws a ClassCastException (as BigIntegers are
comparable only to other BigIntegers).
- Specified by:
compareTo in interface Comparable
- Parameters:
o - Object to which this BigInteger is to be compared.
- Returns:
- a negative number, zero, or a positive number as this
BigInteger is numerically less than, equal to, or greater
than o, which must be a BigInteger.
- Throws:
ClassCastException - o is not a BigInteger.- Since:
- 1.2
- See Also:
compareTo(java.math.BigInteger),
Comparable
intArrayCmp
private static int intArrayCmp(int[] arg1,
int[] arg2)
-
-
equals
public boolean equals(Object x)
- Suppressed: Compares this BigInteger with the specified Object for equality.
- Overrides:
equals in class Object
- Parameters:
x - Object to which this BigInteger is to be compared.
- Returns:
- true if and only if the specified Object is a
BigInteger whose value is numerically equal to this BigInteger.
- See Also:
Object.hashCode(),
java.util.Hashtable
min
public BigInteger min(BigInteger val)
- Enabled: Returns the minimum of this BigInteger and val.
-
- Parameters:
val - value with with the minimum is to be computed.
- Returns:
- the BigInteger whose value is the lesser of this BigInteger and
val. If they are equal, either may be returned.
max
public BigInteger max(BigInteger val)
- Enabled: Returns the maximum of this BigInteger and val.
-
- Parameters:
val - value with with the maximum is to be computed.
- Returns:
- the BigInteger whose value is the greater of this and
val. If they are equal, either may be returned.
hashCode
public int hashCode()
- Suppressed: Returns the hash code for this BigInteger.
- Overrides:
hashCode in class Object
- Returns:
- hash code for this BigInteger.
- See Also:
java.lang.Object#equals(java.lang.Object),
java.util.Hashtable
toString
public String toString(int radix)
- Enabled: Returns the String representation of this BigInteger in the
given radix. If the radix is outside the range from
Character.MIN_RADIX to Character.MAX_RADIX inclusive,
it will default to 10 (as is the case for
Integer.toString). The digit-to-character mapping
provided by Character.forDigit is used, and a minus
sign is prepended if appropriate. (This representation is
compatible with the (String,
int) constructor.)
-
- Parameters:
radix - radix of the String representation.
- Returns:
- String representation of this BigInteger in the given radix.
- See Also:
Integer.toString(int, int),
Character.forDigit(int, int),
BigInteger(java.lang.String, int)
toString
public String toString()
- Suppressed: Returns the decimal String representation of this BigInteger.
The digit-to-character mapping provided by
Character.forDigit is used, and a minus sign is
prepended if appropriate. (This representation is compatible
with the
(String) constructor, and
allows for String concatenation with Java's + operator.)
- Overrides:
toString in class Object
- Returns:
- decimal String representation of this BigInteger.
- See Also:
Character.forDigit(int, int),
BigInteger(java.lang.String)
toByteArray
public byte[] toByteArray()
- Enabled: Returns a byte array containing the two's-complement
representation of this BigInteger. The byte array will be in
big-endian byte-order: the most significant byte is in
the zeroth element. The array will contain the minimum number
of bytes required to represent this BigInteger, including at
least one sign bit, which is (ceil((this.bitLength() +
1)/8)). (This representation is compatible with the
(byte[]) constructor.)
-
- Returns:
- a byte array containing the two's-complement representation of
this BigInteger.
- See Also:
BigInteger(byte[])
intValue
public int intValue()
- Enabled: Converts this BigInteger to an
int. This
conversion is analogous to a narrowing
primitive conversion from long to
int as defined in the Java Language
Specification: if this BigInteger is too big to fit in an
int, only the low-order 32 bits are returned.
Note that this conversion can lose information about the
overall magnitude of the BigInteger value as well as return a
result with the opposite sign.
- Specified by:
intValue in class Number
- Returns:
- this BigInteger converted to an
int.
longValue
public long longValue()
- Enabled: Converts this BigInteger to a
long. This
conversion is analogous to a narrowing
primitive conversion from long to
int as defined in the Java Language
Specification: if this BigInteger is too big to fit in a
long, only the low-order 64 bits are returned.
Note that this conversion can lose information about the
overall magnitude of the BigInteger value as well as return a
result with the opposite sign.
- Specified by:
longValue in class Number
- Returns:
- this BigInteger converted to a
long.
floatValue
public float floatValue()
- Enabled: Converts this BigInteger to a
float. This
conversion is similar to the narrowing
primitive conversion from double to
float defined in the Java Language
Specification: if this BigInteger has too great a magnitude
to represent as a float, it will be converted to
Float.NEGATIVE_INFINITY or Float.POSITIVE_INFINITY as appropriate. Note that even when
the return value is finite, this conversion can lose
information about the precision of the BigInteger value.
- Specified by:
floatValue in class Number
- Returns:
- this BigInteger converted to a
float.
doubleValue
public double doubleValue()
- Enabled: Converts this BigInteger to a
double. This
conversion is similar to the narrowing
primitive conversion from double to
float defined in the Java Language
Specification: if this BigInteger has too great a magnitude
to represent as a double, it will be converted to
Double.NEGATIVE_INFINITY or Double.POSITIVE_INFINITY as appropriate. Note that even when
the return value is finite, this conversion can lose
information about the precision of the BigInteger value.
- Specified by:
doubleValue in class Number
- Returns:
- this BigInteger converted to a
double.
stripLeadingZeroInts
private static int[] stripLeadingZeroInts(int[] val)
- Returns a copy of the input array stripped of any leading zero bytes.
-
-
trustedStripLeadingZeroInts
private static int[] trustedStripLeadingZeroInts(int[] val)
- Returns the input array stripped of any leading zero bytes.
Since the source is trusted the copying may be skipped.
-
-
stripLeadingZeroBytes
private static int[] stripLeadingZeroBytes(byte[] a)
- Returns a copy of the input array stripped of any leading zero bytes.
-
-
makePositive
private static int[] makePositive(byte[] a)
- Takes an array a representing a negative 2's-complement number and
returns the minimal (no leading zero bytes) unsigned whose value is -a.
-
-
makePositive
private static int[] makePositive(int[] a)
- Takes an array a representing a negative 2's-complement number and
returns the minimal (no leading zero ints) unsigned whose value is -a.
-
-
intLength
private int intLength()
- Returns the length of the two's complement representation in ints,
including space for at least one sign bit.
-
-
signBit
private int signBit()
-
-
signInt
private int signInt()
-
-
getInt
private int getInt(int n)
- Returns the specified int of the little-endian two's complement
representation (int 0 is the least significant). The int number can
be arbitrarily high (values are logically preceded by infinitely many
sign ints).
-
-
firstNonzeroIntNum
private int firstNonzeroIntNum()
- Returns the index of the int that contains the first nonzero int in the
little-endian binary representation of the magnitude (int 0 is the
least significant). If the magnitude is zero, return value is undefined.
-
-
readObject
private void readObject(ObjectInputStream s)
throws IOException,
ClassNotFoundException
- Reconstitute the BigInteger instance from a stream (that is,
deserialize it). The magnitude is read in as an array of bytes
for historical reasons, but it is converted to an array of ints
and the byte array is discarded.
-
IOException
ClassNotFoundException
writeObject
private void writeObject(ObjectOutputStream s)
throws IOException
- Save the BigInteger instance to a stream.
The magnitude of a BigInteger is serialized as a byte array for
historical reasons.
-
IOException
magSerializedForm
private byte[] magSerializedForm()
- Returns the mag array as an array of bytes.
-
-
compareTo
public int compareTo(Object o)
- Added: Overrides the inherited 'compareTo' to coerce 'o' to a BigInteger
- Specified by:
compareTo in interface Comparable
- Parameters:
o - the Object to be compared.
- Returns:
- a negative integer, zero, or a positive integer as this object
is less than, equal to, or greater than the specified object.
next
public BigInteger next()
- Added: The next higher integer
-
-
isNaN
public boolean isNaN()
- Added: All integers are numbers, so this is always false
-
-
previous
public BigInteger previous()
- Added: The next lower integer
-
-
ceil
public BigInteger ceil()
- Added: Defined both here and in DoubleSugar, so you can use this to
get a ceil'ed integer no matter what kind of number you start
with. Similarly, the "doubleValue" message will get you a
floating point value no matter what you start with.
-
-
floor
public BigInteger floor()
- Added: Defined both here and in DoubleSugar, so you can use this to
get a floor'ed integer no matter what kind of number you start
with. Similarly, the "doubleValue" message will get you a
floating point value no matter what you start with.
-
-
round
public BigInteger round()
- Added: Defined both here and in DoubleSugar, so you can use this to
get round'ed integer no matter what kind of number you start
with. Similarly, the "doubleValue" message will get you a
floating point value no matter what you start with.
-
-
butNot
public BigInteger butNot(BigInteger arg)
- Added: In E, andNot() is called butNot()
-
-
mod
public BigInteger mod(BigInteger arg)
- Added: Remainder from the floorDivide operation.
(a floorDivide b)*b + (a modulo b) == a
[ 5, 3]: ( 1* 3) + 2 == 5
[ 5,-3]: (-2*-3) + -1 == 5
[-5, 3]: (-2* 3) + 1 == -5
[-5,-3]: ( 1*-3) + -2 == -5
Therefore, if the result is non-zero, the sign of the result must be
the same as the sign of b, and so the result ranges from 0 inclusive
to b exclusive. This corresponds to the E "%%" operator. When
b>= 0, it also corresponds to Java's BigInteger.mod().
-
-
asFloat64
public double asFloat64()
- Added: Returns the "best" IEEE double precision floating point equivalent to
this number. If this number is representable in IEEE double
precision, then that IEEE value is returned. Otherwise, convert by
rounding to even.
-
-
isZero
public boolean isZero()
- Added: Used for arithmetic equality
-
-
asChar
public char asChar()
- Added: Returns the Unicode character with this character code.
-
-
truncate
public BigInteger truncate()
- Added: Defined both here and in DoubleSugar, so you can use this to
get truncate'd integer no matter what kind of number you start
with. Similarly, the "doubleValue" message will get you a
floating point value no matter what you start with.
-
-
approxDivide
public double approxDivide(double arg)
- Added: Always gives back a Double
This corresponds to the Java floating-point "/" operator
and the E "/" operator.
-
-
aboveZero
public boolean aboveZero()
- Added: Used in the expansion of E's ">" operator
-
-
atLeastZero
public boolean atLeastZero()
- Added: Used in the expansion of E's ">=" operator
-
-
atMostZero
public boolean atMostZero()
- Added: Used in the expansion of E's "<=" operator
-
-
belowZero
public boolean belowZero()
- Added: Used in the expansion of E's "<" operator
-
-
complement
public BigInteger complement()
- Deprecated. Use
not() instead.
- Added: This method supports the C-tradition expectation that unary "~" will
work as bit complement.
However, the E style, supported by other set-like abstractions, is to
use unary "!" instead.
-
-
floorDivide
public BigInteger floorDivide(BigInteger arg)
- Added: Always gives an integer, resulting from rounding towards negative
infinity, ie, flooring. This corresponds to the E "_/" operator.
-
-
truncDivide
public BigInteger truncDivide(BigInteger arg)
- Added: Always gives an integer resulting from rounding towards zero,
ie, truncating. This corresponds to the Java integer "/" operator.
BigInteger's existing 'remainder' gives the correct remainder from
the truncDivide operation.
(a truncDivide b)*b + (a remainder b) == a
[ 5, 3]: ( 1* 3) + 2 == 5
[ 5,-3]: (-1*-3) + 2 == 5
[-5, 3]: (-1* 3) + -2 == -5
[-5,-3]: ( 1*-3) + -2 == -5
Therefore, if the result is non-zero, the sign of the result must
be the same as the sign of a. This corresponds to the Java and
E "%" operator.
-
-
toString64
public String toString64()
- Added: Convert an integer to a base 64 string, with an optional leading minus
sign.
A negative integer is encoded as a "-" followed by the encoding of the
absolute magnitude. For a positive integer, the encoded length will
be (4 * b.length)/3, rounded up to the next integral (non-fractional)
character length.
Each base 64 digit is encoded by one of the characters
- '0'..'9' for 0..9
- 'A'..'Z' for 10..35
- 'a'..'z' for 37..61
- '=' for 62
- '_' for 63
-
- Returns:
- a string which represents the integer in base 64 encoding.
cryptoHash
public BigInteger cryptoHash()
- Added: Actually, a SHA hash
-
-
fromString64
public static BigInteger fromString64(String s)
throws NumberFormatException
- Added: Convert a base 64 string to an integer.
-
- Parameters:
s - The string in base 64 notation, with an optional leading
'-', in the format produced by
BigIntegerSugar#toString64(BigInteger).
- Returns:
- the integer.
- Throws:
NumberFormatException - if there is an invalid base 64
character in the input string.