com.helger.commons.math

Class FactorialHelper

java.lang.Object

com.helger.commons.math.FactorialHelper

@Immutable
public final class FactorialHelper
extends Object

Smart class for calculating factorials.

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field and Description
static int	PREDEFINED_MAX_INDEX The maximum value for which pre-computed factorial values are present
static int	PREDEFINED_MIN_INDEX The minimum value for which pre-computed factorial values are present

Method Summary

Methods

Modifier and Type	Method and Description
static BigInteger	getAnyFactorialLinear(int n)
static long	getSmallFactorial(int n) Calculate n!

Methods inherited from class java.lang.Object

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

Field Detail

PREDEFINED_MIN_INDEX

public static final int PREDEFINED_MIN_INDEX

The minimum value for which pre-computed factorial values are present

See Also:

Constant Field Values

PREDEFINED_MAX_INDEX

public static final int PREDEFINED_MAX_INDEX

The maximum value for which pre-computed factorial values are present

Method Detail

getSmallFactorial

@Nonnegative
public static long getSmallFactorial(@Nonnegative
                                 int n)

Calculate n! whereas n must be in the range of 0 to PREDEFINED_MAX_INDEX.

Parameters:

n - Input value

Returns:

The factorial value.

getAnyFactorialLinear

@Nonnull
public static BigInteger getAnyFactorialLinear(@Nonnegative
                                       int n)