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IntMath (Guava: Google Core Libraries for Java 11.0.1 API)























  
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com.google.common.math


Class IntMath
java.lang.Object
  com.google.common.math.IntMath



@Beta
@GwtCompatible(emulated=true)
public final class IntMathextends Object




A class for arithmetic on values of type int. Where possible, methods are defined and
 named analogously to their BigInteger counterparts.

 
The implementations of many methods in this class are based on material from Henry S. Warren,
 Jr.'s Hacker's Delight, (Addison Wesley, 2002).

 
Similar functionality for long and for BigInteger can be found in
 LongMath and BigIntegerMath respectively.  For other common operations on
 int values, see Ints.




Since:
  11.0
Author:
  Louis Wasserman











Method Summary



static int
binomial(int n,
                 int k)



          Returns n choose k, also known as the binomial coefficient of n and
 k, or Integer.MAX_VALUE if the result does not fit in an int.



static int
checkedAdd(int a,
                     int b)



          Returns the sum of a and b, provided it does not overflow.



static int
checkedMultiply(int a,
                               int b)



          Returns the product of a and b, provided it does not overflow.



static int
checkedPow(int b,
                     int k)



          Returns the b to the kth power, provided it does not overflow.



static int
checkedSubtract(int a,
                               int b)



          Returns the difference of a and b, provided it does not overflow.



static int
divide(int p,
             int q,
             RoundingMode mode)



          Returns the result of dividing p by q, rounding using the specified
 RoundingMode.



static int
factorial(int n)



          Returns n!, that is, the product of the first n positive
 integers, 1 if n == 0, or Integer.MAX_VALUE if the
 result does not fit in a int.



static int
gcd(int a,
       int b)



          Returns the greatest common divisor of a, b.



static boolean
isPowerOfTwo(int x)



          Returns true if x represents a power of two.



static int
log10(int x,
           RoundingMode mode)



          Returns the base-10 logarithm of x, rounded according to the specified rounding mode.



static int
log2(int x,
         RoundingMode mode)



          Returns the base-2 logarithm of x, rounded according to the specified rounding mode.



static int
mod(int x,
       int m)



          Returns x mod m.



static int
pow(int b,
       int k)



          Returns b to the kth power.



static int
sqrt(int x,
         RoundingMode mode)



          Returns the square root of x, rounded with the specified rounding mode.


 


Methods inherited from class java.lang.Object


clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait


 








Method Detail




isPowerOfTwo
public static boolean isPowerOfTwo(int x)

Returns true if x represents a power of two.

 This differs from Integer.bitCount(x) == 1, because
 Integer.bitCount(Integer.MIN_VALUE) == 1, but Integer.MIN_VALUE is not a power
 of two.








log2
@GwtIncompatible(value="need BigIntegerMath to adequately test")
public static int log2(int x,
                                            RoundingMode mode)

Returns the base-2 logarithm of x, rounded according to the specified rounding mode.



Throws:
IllegalArgumentException - if x <= 0
ArithmeticException - if mode is RoundingMode.UNNECESSARY and x
         is not a power of two





log10
@GwtIncompatible(value="need BigIntegerMath to adequately test")
public static int log10(int x,
                                             RoundingMode mode)

Returns the base-10 logarithm of x, rounded according to the specified rounding mode.



Throws:
IllegalArgumentException - if x <= 0
ArithmeticException - if mode is RoundingMode.UNNECESSARY and x
         is not a power of ten





pow
@GwtIncompatible(value="failing tests")
public static int pow(int b,
                                           int k)

Returns b to the kth power. Even if the result overflows, it will be equal to
 BigInteger.valueOf(b).pow(k).intValue(). This implementation runs in O(log k)
 time.

 Compare checkedPow(int, int), which throws an ArithmeticException upon overflow.



Throws:
IllegalArgumentException - if k < 0





sqrt
@GwtIncompatible(value="need BigIntegerMath to adequately test")
public static int sqrt(int x,
                                            RoundingMode mode)

Returns the square root of x, rounded with the specified rounding mode.



Throws:
IllegalArgumentException - if x < 0
ArithmeticException - if mode is RoundingMode.UNNECESSARY and
         sqrt(x) is not an integer





divide
@GwtIncompatible(value="failing tests")
public static int divide(int p,
                                              int q,
                                              RoundingMode mode)

Returns the result of dividing p by q, rounding using the specified
 RoundingMode.



Throws:
ArithmeticException - if q == 0, or if mode == UNNECESSARY and a
         is not an integer multiple of b





mod
public static int mod(int x,
                      int m)

Returns x mod m. This differs from x % m in that it always returns a
 non-negative result.

 For example:
 mod(7, 4) == 3
 mod(-7, 4) == 1
 mod(-1, 4) == 3
 mod(-8, 4) == 0
 mod(8, 4) == 0



Throws:
ArithmeticException - if m <= 0





gcd
public static int gcd(int a,
                      int b)

Returns the greatest common divisor of a, b. Returns 0 if
 a == 0 && b == 0.



Throws:
IllegalArgumentException - if a < 0 or b < 0





checkedAdd
public static int checkedAdd(int a,
                             int b)

Returns the sum of a and b, provided it does not overflow.



Throws:
ArithmeticException - if a + b overflows in signed int arithmetic





checkedSubtract
public static int checkedSubtract(int a,
                                  int b)

Returns the difference of a and b, provided it does not overflow.



Throws:
ArithmeticException - if a - b overflows in signed int arithmetic





checkedMultiply
public static int checkedMultiply(int a,
                                  int b)

Returns the product of a and b, provided it does not overflow.



Throws:
ArithmeticException - if a * b overflows in signed int arithmetic





checkedPow
@GwtIncompatible(value="failing tests")
public static int checkedPow(int b,
                                                  int k)

Returns the b to the kth power, provided it does not overflow.

 pow(int, int) may be faster, but does not check for overflow.



Throws:
ArithmeticException - if b to the kth power overflows in signed
         int arithmetic





factorial
@GwtIncompatible(value="need BigIntegerMath to adequately test")
public static int factorial(int n)

Returns n!, that is, the product of the first n positive
 integers, 1 if n == 0, or Integer.MAX_VALUE if the
 result does not fit in a int.



Throws:
IllegalArgumentException - if n < 0





binomial
@GwtIncompatible(value="need BigIntegerMath to adequately test")
public static int binomial(int n,
                                                int k)

Returns n choose k, also known as the binomial coefficient of n and
 k, or Integer.MAX_VALUE if the result does not fit in an int.



Throws:
IllegalArgumentException - if n < 0, k < 0 or k > n














  
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Copyright © 2010-2012. All Rights Reserved.

Method Summary
`static int`	`binomial(int n, int k)` Returns `n` choose `k`, also known as the binomial coefficient of `n` and `k`, or `Integer.MAX_VALUE` if the result does not fit in an `int`.
`static int`	`checkedAdd(int a, int b)` Returns the sum of `a` and `b`, provided it does not overflow.
`static int`	`checkedMultiply(int a, int b)` Returns the product of `a` and `b`, provided it does not overflow.
`static int`	`checkedPow(int b, int k)` Returns the `b` to the `k`th power, provided it does not overflow.
`static int`	`checkedSubtract(int a, int b)` Returns the difference of `a` and `b`, provided it does not overflow.
`static int`	`divide(int p, int q, RoundingMode mode)` Returns the result of dividing `p` by `q`, rounding using the specified `RoundingMode`.
`static int`	`factorial(int n)` Returns `n!`, that is, the product of the first `n` positive integers, `1` if `n == 0`, or `Integer.MAX_VALUE` if the result does not fit in a `int`.
`static int`	`gcd(int a, int b)` Returns the greatest common divisor of `a, b`.
`static boolean`	`isPowerOfTwo(int x)` Returns `true` if `x` represents a power of two.
`static int`	`log10(int x, RoundingMode mode)` Returns the base-10 logarithm of `x`, rounded according to the specified rounding mode.
`static int`	`log2(int x, RoundingMode mode)` Returns the base-2 logarithm of `x`, rounded according to the specified rounding mode.
`static int`	`mod(int x, int m)` Returns `x mod m`.
`static int`	`pow(int b, int k)` Returns `b` to the `k`th power.
`static int`	`sqrt(int x, RoundingMode mode)` Returns the square root of `x`, rounded with the specified rounding mode.

javadoc.com.google.common.math.IntMath.html Maven / Gradle / Ivy

com.google.common.math Class IntMath

isPowerOfTwo

log2

log10

pow

sqrt

divide

mod

gcd

checkedAdd

checkedSubtract

checkedMultiply

checkedPow

factorial

binomial

com.google.common.math
Class IntMath