BigInteger
public
class
BigInteger
extends Number
implements
Comparable<BigInteger>
java.lang.Object | ||
↳ | java.lang.Number | |
↳ | java.math.BigInteger |
Immutable arbitrary-precision integers. All operations behave as if BigIntegers were represented in two's-complement notation (like Java's primitive integer types). BigInteger provides analogues to all of Java's primitive integer operators, and all relevant methods from java.lang.Math. Additionally, BigInteger provides operations for modular arithmetic, GCD calculation, primality testing, prime generation, bit manipulation, and a few other miscellaneous operations.
Semantics of arithmetic operations exactly mimic those of Java's integer
arithmetic operators, as defined in The Java Language Specification.
For example, division by zero throws an ArithmeticException
, and
division of a negative by a positive yields a negative (or zero) remainder.
Semantics of shift operations extend those of Java's shift operators
to allow for negative shift distances. A right-shift with a negative
shift distance results in a left shift, and vice-versa. The unsigned
right shift operator (>>>
) is omitted since this operation
only makes sense for a fixed sized word and not for a
representation conceptually having an infinite number of leading
virtual sign bits.
Semantics of bitwise logical operations exactly mimic those of Java's
bitwise integer operators. The binary operators (and
,
or
, xor
) implicitly perform sign extension on the shorter
of the two operands prior to performing the operation.
Comparison operations perform signed integer comparisons, analogous to those performed by Java's relational and equality operators.
Modular arithmetic operations are provided to compute residues, perform
exponentiation, and compute multiplicative inverses. These methods always
return a non-negative result, between 0
and (modulus - 1)
,
inclusive.
Bit operations operate on a single bit of the two's-complement representation of their operand. If necessary, the operand is sign-extended so that it contains the designated bit. None of the single-bit operations can produce a BigInteger with a different sign from the BigInteger being operated on, as they affect only a single bit, and the arbitrarily large abstraction provided by this class ensures that conceptually there are infinitely many "virtual sign bits" preceding each BigInteger.
For the sake of brevity and clarity, pseudo-code is used throughout the
descriptions of BigInteger methods. The pseudo-code expression
(i + j)
is shorthand for "a BigInteger whose value is
that of the BigInteger i
plus that of the BigInteger j
."
The pseudo-code expression (i == j)
is shorthand for
"true
if and only if the BigInteger i
represents the same
value as the BigInteger j
." Other pseudo-code expressions are
interpreted similarly.
All methods and constructors in this class throw
NullPointerException
when passed
a null object reference for any input parameter.
BigInteger must support values in the range
-2Integer.MAX_VALUE
(exclusive) to
+2Integer.MAX_VALUE
(exclusive)
and may support values outside of that range.
An ArithmeticException
is thrown when a BigInteger
constructor or method would generate a value outside of the
supported range.
The range of probable prime values is limited and may be less than
the full supported positive range of BigInteger
.
The range must be at least 1 to 2500000000.
See also:
Summary
Fields | |
---|---|
public
static
final
BigInteger |
ONE
The BigInteger constant one. |
public
static
final
BigInteger |
TEN
The BigInteger constant ten. |
public
static
final
BigInteger |
TWO
The BigInteger constant two. |
public
static
final
BigInteger |
ZERO
The BigInteger constant zero. |
Public constructors | |
---|---|
BigInteger(byte[] val)
Translates a byte array containing the two's-complement binary representation of a BigInteger into a BigInteger. |
|
BigInteger(byte[] val, int off, int len)
Translates a byte sub-array containing the two's-complement binary representation of a BigInteger into a BigInteger. |
|
BigInteger(int signum, byte[] magnitude)
Translates the sign-magnitude representation of a BigInteger into a BigInteger. |
|
BigInteger(int signum, byte[] magnitude, int off, int len)
Translates the sign-magnitude representation of a BigInteger into a BigInteger. |
|
BigInteger(int bitLength, int certainty, Random rnd)
Constructs a randomly generated positive BigInteger that is probably prime, with the specified bitLength. |
|
BigInteger(int numBits, Random rnd)
Constructs a randomly generated BigInteger, uniformly distributed over
the range 0 to (2 |
|
BigInteger(String val)
Translates the decimal String representation of a BigInteger into a BigInteger. |
|
BigInteger(String val, int radix)
Translates the String representation of a BigInteger in the specified radix into a BigInteger. |
Public methods | |
---|---|
BigInteger
|
abs()
Returns a BigInteger whose value is the absolute value of this BigInteger. |
BigInteger
|
add(BigInteger val)
Returns a BigInteger whose value is |
BigInteger
|
and(BigInteger val)
Returns a BigInteger whose value is |
BigInteger
|
andNot(BigInteger val)
Returns a BigInteger whose value is |
int
|
bitCount()
Returns the number of bits in the two's complement representation of this BigInteger that differ from its sign bit. |
int
|
bitLength()
Returns the number of bits in the minimal two's-complement representation of this BigInteger, excluding a sign bit. |
byte
|
byteValueExact()
Converts this |
BigInteger
|
clearBit(int n)
Returns a BigInteger whose value is equivalent to this BigInteger with the designated bit cleared. |
int
|
compareTo(BigInteger val)
Compares this BigInteger with the specified BigInteger. |
BigInteger
|
divide(BigInteger val)
Returns a BigInteger whose value is |
BigInteger[]
|
divideAndRemainder(BigInteger val)
Returns an array of two BigIntegers containing |
double
|
doubleValue()
Converts this BigInteger to a |
boolean
|
equals(Object x)
Compares this BigInteger with the specified Object for equality. |
BigInteger
|
flipBit(int n)
Returns a BigInteger whose value is equivalent to this BigInteger with the designated bit flipped. |
float
|
floatValue()
Converts this BigInteger to a |
BigInteger
|
gcd(BigInteger val)
Returns a BigInteger whose value is the greatest common divisor of
|
int
|
getLowestSetBit()
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()
Returns the hash code for this BigInteger. |
int
|
intValue()
Converts this BigInteger to an |
int
|
intValueExact()
Converts this |
boolean
|
isProbablePrime(int certainty)
Returns |
long
|
longValue()
Converts this BigInteger to a |
long
|
longValueExact()
Converts this |
BigInteger
|
max(BigInteger val)
Returns the maximum of this BigInteger and |
BigInteger
|
min(BigInteger val)
Returns the minimum of this BigInteger and |
BigInteger
|
mod(BigInteger m)
Returns a BigInteger whose value is |
BigInteger
|
modInverse(BigInteger m)
Returns a BigInteger whose value is |
BigInteger
|
modPow(BigInteger exponent, BigInteger m)
Returns a BigInteger whose value is
|
BigInteger
|
multiply(BigInteger val)
Returns a BigInteger whose value is |
BigInteger
|
negate()
Returns a BigInteger whose value is |
BigInteger
|
nextProbablePrime()
Returns the first integer greater than this |
BigInteger
|
not()
Returns a BigInteger whose value is |
BigInteger
|
or(BigInteger val)
Returns a BigInteger whose value is |
BigInteger
|
pow(int exponent)
Returns a BigInteger whose value is |
static
BigInteger
|
probablePrime(int bitLength, Random rnd)
Returns a positive BigInteger that is probably prime, with the specified bitLength. |
BigInteger
|
remainder(BigInteger val)
Returns a BigInteger whose value is |
BigInteger
|
setBit(int n)
Returns a BigInteger whose value is equivalent to this BigInteger with the designated bit set. |
BigInteger
|
shiftLeft(int n)
Returns a BigInteger whose value is |
BigInteger
|
shiftRight(int n)
Returns a BigInteger whose value is |
short
|
shortValueExact()
Converts this |
int
|
signum()
Returns the signum function of this BigInteger. |
BigInteger
|
sqrt()
Returns the integer square root of this BigInteger. |
BigInteger[]
|
sqrtAndRemainder()
Returns an array of two BigIntegers containing the integer square root
|
BigInteger
|
subtract(BigInteger val)
Returns a BigInteger whose value is |
boolean
|
testBit(int n)
Returns |
byte[]
|
toByteArray()
Returns a byte array containing the two's-complement representation of this BigInteger. |
String
|
toString()
Returns the decimal String representation of this BigInteger. |
String
|
toString(int radix)
Returns the String representation of this BigInteger in the given radix. |
static
BigInteger
|
valueOf(long val)
Returns a BigInteger whose value is equal to that of the
specified |
BigInteger
|
xor(BigInteger val)
Returns a BigInteger whose value is |
Inherited methods | |
---|---|
Fields
Public constructors
BigInteger
public BigInteger (byte[] val)
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. The val
array is assumed to be
unchanged for the duration of the constructor call.
Parameters | |
---|---|
val |
byte : big-endian two's-complement binary representation of a
BigInteger. |
Throws | |
---|---|
NumberFormatException |
val is zero bytes long. |
BigInteger
public BigInteger (byte[] val, int off, int len)
Translates a byte sub-array containing the two's-complement binary
representation of a BigInteger into a BigInteger. The sub-array is
specified via an offset into the array and a length. The sub-array is
assumed to be in big-endian byte-order: the most significant
byte is the element at index off
. The val
array is
assumed to be unchanged for the duration of the constructor call.
An IndexOutOfBoundsException
is thrown if the length of the array
val
is non-zero and either off
is negative, len
is negative, or off+len
is greater than the length of
val
.
Parameters | |
---|---|
val |
byte : byte array containing a sub-array which is the big-endian
two's-complement binary representation of a BigInteger. |
off |
int : the start offset of the binary representation. |
len |
int : the number of bytes to use. |
Throws | |
---|---|
NumberFormatException |
val is zero bytes long. |
IndexOutOfBoundsException |
if the provided array offset and length would cause an index into the byte array to be negative or greater than or equal to the array length. |
BigInteger
public BigInteger (int signum, byte[] magnitude)
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 the
zeroth element. A zero-length magnitude array is permissible, and will
result in a BigInteger value of 0, whether signum is -1, 0 or 1. The
magnitude
array is assumed to be unchanged for the duration of
the constructor call.
Parameters | |
---|---|
signum |
int : signum of the number (-1 for negative, 0 for zero, 1
for positive). |
magnitude |
byte : 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
public BigInteger (int signum, byte[] magnitude, int off, int len)
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 sub-array of
a byte array in big-endian byte-order: the most significant byte
is the element at index off
. A zero value of the length
len
is permissible, and will result in a BigInteger value of 0,
whether signum is -1, 0 or 1. The magnitude
array is assumed to
be unchanged for the duration of the constructor call.
An IndexOutOfBoundsException
is thrown if the length of the array
magnitude
is non-zero and either off
is negative,
len
is negative, or off+len
is greater than the length of
magnitude
.
Parameters | |
---|---|
signum |
int : signum of the number (-1 for negative, 0 for zero, 1
for positive). |
magnitude |
byte : big-endian binary representation of the magnitude of
the number. |
off |
int : the start offset of the binary representation. |
len |
int : the number of bytes to use. |
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. |
IndexOutOfBoundsException |
if the provided array offset and length would cause an index into the byte array to be negative or greater than or equal to the array length. |
BigInteger
public BigInteger (int bitLength, int certainty, Random rnd)
Constructs a randomly generated positive BigInteger that is probably prime, with the specified bitLength.
API Note:
- 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 |
int : bitLength of the returned BigInteger. |
certainty |
int : 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 |
Random : source of random bits used to select candidates to be
tested for primality. |
Throws | |
---|---|
ArithmeticException |
bitLength < 2 or bitLength is too large. |
See also:
BigInteger
public BigInteger (int numBits, Random rnd)
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 |
int : maximum bitLength of the new BigInteger. |
rnd |
Random : source of randomness to be used in computing the new
BigInteger. |
Throws | |
---|---|
IllegalArgumentException |
numBits is negative. |
See also:
BigInteger
public BigInteger (String val)
Translates the decimal String representation of a BigInteger
into a BigInteger. The String representation consists of an
optional minus or plus 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 |
String : decimal String representation of BigInteger. |
Throws | |
---|---|
NumberFormatException |
val is not a valid representation
of a BigInteger. |
BigInteger
public BigInteger (String val, int radix)
Translates the String representation of a BigInteger in the
specified radix into a BigInteger. The String representation
consists of an optional minus or plus 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 : String representation of BigInteger. |
radix |
int : 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. |
Public methods
abs
public BigInteger abs ()
Returns a BigInteger whose value is the absolute value of this BigInteger.
Returns | |
---|---|
BigInteger |
abs(this) |
add
public BigInteger add (BigInteger val)
Returns a BigInteger whose value is (this + val)
.
Parameters | |
---|---|
val |
BigInteger : value to be added to this BigInteger. |
Returns | |
---|---|
BigInteger |
this + val |
and
public BigInteger and (BigInteger val)
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 |
BigInteger : value to be AND'ed with this BigInteger. |
Returns | |
---|---|
BigInteger |
this & val |
andNot
public BigInteger andNot (BigInteger val)
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 |
BigInteger : value to be complemented and AND'ed with this BigInteger. |
Returns | |
---|---|
BigInteger |
this & ~val |
bitCount
public int bitCount ()
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 | |
---|---|
int |
number of bits in the two's complement representation of this BigInteger that differ from its sign bit. |
bitLength
public int bitLength ()
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. For zero this method returns
0
. (Computes (ceil(log2(this < 0 ? -this : this+1)))
.)
Returns | |
---|---|
int |
number of bits in the minimal two's-complement representation of this BigInteger, excluding a sign bit. |
byteValueExact
public byte byteValueExact ()
Converts this BigInteger
to a byte
, checking
for lost information. If the value of this BigInteger
is out of the range of the byte
type, then an
ArithmeticException
is thrown.
Returns | |
---|---|
byte |
this BigInteger converted to a byte . |
Throws | |
---|---|
ArithmeticException |
if the value of this will
not exactly fit in a byte . |
See also:
clearBit
public BigInteger clearBit (int n)
Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit cleared.
(Computes (this & ~(1<<n))
.)
Parameters | |
---|---|
n |
int : index of bit to clear. |
Returns | |
---|---|
BigInteger |
this & ~(1<<n) |
Throws | |
---|---|
ArithmeticException |
n is negative. |
compareTo
public int compareTo (BigInteger val)
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 : BigInteger to which this BigInteger is to be compared. |
Returns | |
---|---|
int |
-1, 0 or 1 as this BigInteger is numerically less than, equal
to, or greater than val . |
divide
public BigInteger divide (BigInteger val)
Returns a BigInteger whose value is (this / val)
.
Parameters | |
---|---|
val |
BigInteger : value by which this BigInteger is to be divided. |
Returns | |
---|---|
BigInteger |
this / val |
Throws | |
---|---|
ArithmeticException |
if val is zero. |
divideAndRemainder
public BigInteger[] divideAndRemainder (BigInteger val)
Returns an array of two BigIntegers containing (this / val)
followed by (this % val)
.
Parameters | |
---|---|
val |
BigInteger : value by which this BigInteger is to be divided, and the
remainder computed. |
Returns | |
---|---|
BigInteger[] |
an array of two BigIntegers: the quotient (this / val)
is the initial element, and the remainder (this % val)
is the final element. |
Throws | |
---|---|
ArithmeticException |
if val is zero. |
doubleValue
public double doubleValue ()
Converts this BigInteger to a double
. This
conversion is similar to the
narrowing primitive conversion from double
to
float
as 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.
Returns | |
---|---|
double |
this BigInteger converted to a double . |
equals
public boolean equals (Object x)
Compares this BigInteger with the specified Object for equality.
Parameters | |
---|---|
x |
Object : Object to which this BigInteger is to be compared. |
Returns | |
---|---|
boolean |
true if and only if the specified Object is a
BigInteger whose value is numerically equal to this BigInteger. |
flipBit
public BigInteger flipBit (int n)
Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit flipped.
(Computes (this ^ (1<<n))
.)
Parameters | |
---|---|
n |
int : index of bit to flip. |
Returns | |
---|---|
BigInteger |
this ^ (1<<n) |
Throws | |
---|---|
ArithmeticException |
n is negative. |
floatValue
public float floatValue ()
Converts this BigInteger to a float
. This
conversion is similar to the
narrowing primitive conversion from double
to
float
as 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.
Returns | |
---|---|
float |
this BigInteger converted to a float . |
gcd
public BigInteger gcd (BigInteger val)
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 |
BigInteger : value with which the GCD is to be computed. |
Returns | |
---|---|
BigInteger |
GCD(abs(this), abs(val)) |
getLowestSetBit
public int getLowestSetBit ()
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 | |
---|---|
int |
index of the rightmost one bit in this BigInteger. |
hashCode
public int hashCode ()
Returns the hash code for this BigInteger.
Returns | |
---|---|
int |
hash code for this BigInteger. |
intValue
public int intValue ()
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.
Returns | |
---|---|
int |
this BigInteger converted to an int . |
See also:
intValueExact
public int intValueExact ()
Converts this BigInteger
to an int
, checking
for lost information. If the value of this BigInteger
is out of the range of the int
type, then an
ArithmeticException
is thrown.
Returns | |
---|---|
int |
this BigInteger converted to an int . |
Throws | |
---|---|
ArithmeticException |
if the value of this will
not exactly fit in an int . |
See also:
isProbablePrime
public boolean isProbablePrime (int certainty)
Returns true
if this BigInteger is probably prime,
false
if it's definitely composite. If
certainty
is ≤ 0, true
is
returned.
Parameters | |
---|---|
certainty |
int : 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 | |
---|---|
boolean |
true if this BigInteger is probably prime,
false if it's definitely composite. |
longValue
public long longValue ()
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.
Returns | |
---|---|
long |
this BigInteger converted to a long . |
See also:
longValueExact
public long longValueExact ()
Converts this BigInteger
to a long
, checking
for lost information. If the value of this BigInteger
is out of the range of the long
type, then an
ArithmeticException
is thrown.
Returns | |
---|---|
long |
this BigInteger converted to a long . |
Throws | |
---|---|
ArithmeticException |
if the value of this will
not exactly fit in a long . |
See also:
max
public BigInteger max (BigInteger val)
Returns the maximum of this BigInteger and val
.
Parameters | |
---|---|
val |
BigInteger : value with which the maximum is to be computed. |
Returns | |
---|---|
BigInteger |
the BigInteger whose value is the greater of this and
val . If they are equal, either may be returned. |
min
public BigInteger min (BigInteger val)
Returns the minimum of this BigInteger and val
.
Parameters | |
---|---|
val |
BigInteger : value with which the minimum is to be computed. |
Returns | |
---|---|
BigInteger |
the BigInteger whose value is the lesser of this BigInteger and
val . If they are equal, either may be returned. |
mod
public BigInteger mod (BigInteger m)
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 |
BigInteger : the modulus. |
Returns | |
---|---|
BigInteger |
this mod m |
Throws | |
---|---|
ArithmeticException |
m ≤ 0 |
See also:
modInverse
public BigInteger modInverse (BigInteger m)
Returns a BigInteger whose value is (this
-1 mod m)
.
Parameters | |
---|---|
m |
BigInteger : the modulus. |
Returns | |
---|---|
BigInteger |
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). |
modPow
public BigInteger modPow (BigInteger exponent, BigInteger m)
Returns a BigInteger whose value is
(thisexponent mod m)
. (Unlike pow
, this
method permits negative exponents.)
Parameters | |
---|---|
exponent |
BigInteger : the exponent. |
m |
BigInteger : the modulus. |
Returns | |
---|---|
BigInteger |
thisexponent mod m |
Throws | |
---|---|
ArithmeticException |
m ≤ 0 or the exponent is
negative and this BigInteger is not relatively
prime to m . |
See also:
multiply
public BigInteger multiply (BigInteger val)
Returns a BigInteger whose value is (this * val)
.
Implementation Note:
- An implementation may offer better algorithmic
performance when
val == this
.
Parameters | |
---|---|
val |
BigInteger : value to be multiplied by this BigInteger. |
Returns | |
---|---|
BigInteger |
this * val |
negate
public BigInteger negate ()
Returns a BigInteger whose value is (-this)
.
Returns | |
---|---|
BigInteger |
-this |
nextProbablePrime
public BigInteger nextProbablePrime ()
Returns the first integer greater than this BigInteger
that
is probably prime. The probability that the number returned by this
method is composite does not exceed 2-100. This method will
never skip over a prime when searching: if it returns p
, there
is no prime q
such that this < q < p
.
Returns | |
---|---|
BigInteger |
the first integer greater than this BigInteger that
is probably prime. |
Throws | |
---|---|
ArithmeticException |
this < 0 or this is too large. |
not
public BigInteger not ()
Returns a BigInteger whose value is (~this)
. (This method
returns a negative value if and only if this BigInteger is
non-negative.)
Returns | |
---|---|
BigInteger |
~this |
or
public BigInteger or (BigInteger val)
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 |
BigInteger : value to be OR'ed with this BigInteger. |
Returns | |
---|---|
BigInteger |
this | val |
pow
public BigInteger pow (int exponent)
Returns a BigInteger whose value is (thisexponent)
.
Note that exponent
is an integer rather than a BigInteger.
Parameters | |
---|---|
exponent |
int : exponent to which this BigInteger is to be raised. |
Returns | |
---|---|
BigInteger |
thisexponent |
Throws | |
---|---|
ArithmeticException |
exponent is negative. (This would
cause the operation to yield a non-integer value.) |
probablePrime
public static BigInteger probablePrime (int bitLength, Random rnd)
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 |
int : bitLength of the returned BigInteger. |
rnd |
Random : source of random bits used to select candidates to be
tested for primality. |
Returns | |
---|---|
BigInteger |
a BigInteger of bitLength bits that is probably prime |
Throws | |
---|---|
ArithmeticException |
bitLength < 2 or bitLength is too large. |
See also:
remainder
public BigInteger remainder (BigInteger val)
Returns a BigInteger whose value is (this % val)
.
Parameters | |
---|---|
val |
BigInteger : value by which this BigInteger is to be divided, and the
remainder computed. |
Returns | |
---|---|
BigInteger |
this % val |
Throws | |
---|---|
ArithmeticException |
if val is zero. |
setBit
public BigInteger setBit (int n)
Returns a BigInteger whose value is equivalent to this BigInteger
with the designated bit set. (Computes (this | (1<<n))
.)
Parameters | |
---|---|
n |
int : index of bit to set. |
Returns | |
---|---|
BigInteger |
this | (1<<n) |
Throws | |
---|---|
ArithmeticException |
n is negative. |
shiftLeft
public BigInteger shiftLeft (int n)
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 |
int : shift distance, in bits. |
Returns | |
---|---|
BigInteger |
this << n |
See also:
shiftRight
public BigInteger shiftRight (int n)
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 |
int : shift distance, in bits. |
Returns | |
---|---|
BigInteger |
this >> n |
See also:
shortValueExact
public short shortValueExact ()
Converts this BigInteger
to a short
, checking
for lost information. If the value of this BigInteger
is out of the range of the short
type, then an
ArithmeticException
is thrown.
Returns | |
---|---|
short |
this BigInteger converted to a short . |
Throws | |
---|---|
ArithmeticException |
if the value of this will
not exactly fit in a short . |
See also:
signum
public int signum ()
Returns the signum function of this BigInteger.
Returns | |
---|---|
int |
-1, 0 or 1 as the value of this BigInteger is negative, zero or positive. |
sqrt
public BigInteger sqrt ()
Returns the integer square root of this BigInteger. The integer square
root of the corresponding mathematical integer n
is the largest
mathematical integer s
such that s*s <= n
. It is equal
to the value of floor(sqrt(n))
, where sqrt(n)
denotes the
real square root of n
treated as a real. Note that the integer
square root will be less than the real square root if the latter is not
representable as an integral value.
Returns | |
---|---|
BigInteger |
the integer square root of this |
Throws | |
---|---|
ArithmeticException |
if this is negative. (The square
root of a negative integer val is
(i * sqrt(-val)) where i is the
imaginary unit and is equal to
sqrt(-1) .) |
sqrtAndRemainder
public BigInteger[] sqrtAndRemainder ()
Returns an array of two BigIntegers containing the integer square root
s
of this
and its remainder this - s*s
,
respectively.
Returns | |
---|---|
BigInteger[] |
an array of two BigIntegers with the integer square root at offset 0 and the remainder at offset 1 |
Throws | |
---|---|
ArithmeticException |
if this is negative. (The square
root of a negative integer val is
(i * sqrt(-val)) where i is the
imaginary unit and is equal to
sqrt(-1) .) |
See also:
subtract
public BigInteger subtract (BigInteger val)
Returns a BigInteger whose value is (this - val)
.
Parameters | |
---|---|
val |
BigInteger : value to be subtracted from this BigInteger. |
Returns | |
---|---|
BigInteger |
this - val |
testBit
public boolean testBit (int n)
Returns true
if and only if the designated bit is set.
(Computes ((this & (1<<n)) != 0)
.)
Parameters | |
---|---|
n |
int : index of bit to test. |
Returns | |
---|---|
boolean |
true if and only if the designated bit is set. |
Throws | |
---|---|
ArithmeticException |
n is negative. |
toByteArray
public byte[] toByteArray ()
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 | |
---|---|
byte[] |
a byte array containing the two's-complement representation of this BigInteger. |
See also:
toString
public String toString ()
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.)
Returns | |
---|---|
String |
decimal String representation of this BigInteger. |
toString
public String toString (int radix)
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 |
int : radix of the String representation. |
Returns | |
---|---|
String |
String representation of this BigInteger in the given radix. |
valueOf
public static BigInteger valueOf (long val)
Returns a BigInteger whose value is equal to that of the
specified long
.
API Note:
- This static factory method is provided in preference
to a (
long
) constructor because it allows for reuse of frequently used BigIntegers.
Parameters | |
---|---|
val |
long : value of the BigInteger to return. |
Returns | |
---|---|
BigInteger |
a BigInteger with the specified value. |
xor
public BigInteger xor (BigInteger val)
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 |
BigInteger : value to be XOR'ed with this BigInteger. |
Returns | |
---|---|
BigInteger |
this ^ val |