Class LongMath

java.lang.Object
com.google.common.math.LongMath

@GwtCompatible(emulated=true) @Deprecated(since="2022-12-01") public final class LongMath extends Object
Deprecated.
The Google Guava Core Libraries are deprecated and will not be part of the AEM SDK after April 2023
A class for arithmetic on values of type long. 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 int and for BigInteger can be found in IntMath and BigIntegerMath respectively. For other common operations on long values, see Longs.

Since:
11.0
  • Method Summary

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

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Method Details

    • isPowerOfTwo

      public static boolean isPowerOfTwo(long x)
      Deprecated.
      Returns true if x represents a power of two.

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

    • log2

      public static int log2(long x, RoundingMode mode)
      Deprecated.
      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("TODO") public static int log10(long x, RoundingMode mode)
      Deprecated.
      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("TODO") public static long pow(long b, int k)
      Deprecated.
      Returns b to the kth power. Even if the result overflows, it will be equal to BigInteger.valueOf(b).pow(k).longValue(). This implementation runs in O(log k) time.
      Throws:
      IllegalArgumentException - if k < 0
    • sqrt

      @GwtIncompatible("TODO") public static long sqrt(long x, RoundingMode mode)
      Deprecated.
      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("TODO") public static long divide(long p, long q, RoundingMode mode)
      Deprecated.
      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

      @GwtIncompatible("TODO") public static int mod(long x, int m)
      Deprecated.
      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
    • mod

      @GwtIncompatible("TODO") public static long mod(long x, long m)
      Deprecated.
      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 long gcd(long a, long b)
      Deprecated.
      Returns the greatest common divisor of a, b. Returns 0 if a == 0 && b == 0.
      Throws:
      IllegalArgumentException - if a < 0 or b < 0
    • checkedAdd

      @GwtIncompatible("TODO") public static long checkedAdd(long a, long b)
      Deprecated.
      Returns the sum of a and b, provided it does not overflow.
      Throws:
      ArithmeticException - if a + b overflows in signed long arithmetic
    • checkedSubtract

      @GwtIncompatible("TODO") public static long checkedSubtract(long a, long b)
      Deprecated.
      Returns the difference of a and b, provided it does not overflow.
      Throws:
      ArithmeticException - if a - b overflows in signed long arithmetic
    • checkedMultiply

      @GwtIncompatible("TODO") public static long checkedMultiply(long a, long b)
      Deprecated.
      Returns the product of a and b, provided it does not overflow.
      Throws:
      ArithmeticException - if a * b overflows in signed long arithmetic
    • checkedPow

      @GwtIncompatible("TODO") public static long checkedPow(long b, int k)
      Deprecated.
      Returns the b to the kth power, provided it does not overflow.
      Throws:
      ArithmeticException - if b to the kth power overflows in signed long arithmetic
    • factorial

      @GwtIncompatible("TODO") public static long factorial(int n)
      Deprecated.
      Returns n!, that is, the product of the first n positive integers, 1 if n == 0, or Long.MAX_VALUE if the result does not fit in a long.
      Throws:
      IllegalArgumentException - if n < 0
    • binomial

      public static long binomial(int n, int k)
      Deprecated.
      Returns n choose k, also known as the binomial coefficient of n and k, or Long.MAX_VALUE if the result does not fit in a long.
      Throws:
      IllegalArgumentException - if n < 0, k < 0, or k > n
    • mean

      public static long mean(long x, long y)
      Deprecated.
      Returns the arithmetic mean of x and y, rounded toward negative infinity. This method is resilient to overflow.
      Since:
      14.0