Class Primes
java.lang.Object
org.apache.commons.numbers.primes.Primes
Methods related to prime numbers in the range of
int
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- primality test
- prime number generation
- factorization
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Field Summary
FieldsModifier and TypeFieldDescription(package private) static final String
Exception message format when an argument is too small. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic boolean
isPrime
(int n) Primality test: tells if the argument is a (provable) prime or not.static int
nextPrime
(int n) Return the smallest prime greater than or equal to n.primeFactors
(int n) Prime factors decomposition.
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Field Details
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NUMBER_TOO_SMALL
Exception message format when an argument is too small.- See Also:
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Constructor Details
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Primes
private Primes()Utility class.
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Method Details
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isPrime
public static boolean isPrime(int n) Primality test: tells if the argument is a (provable) prime or not.It uses the Miller-Rabin probabilistic test in such a way that a result is guaranteed: it uses the firsts prime numbers as successive base (see Handbook of applied cryptography by Menezes, table 4.1).
- Parameters:
n
- Number to test.- Returns:
- true if
n
is prime. All numbers < 2 return false.
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nextPrime
public static int nextPrime(int n) Return the smallest prime greater than or equal to n.- Parameters:
n
- Positive number.- Returns:
- the smallest prime greater than or equal to
n
. - Throws:
IllegalArgumentException
- if n < 0.
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primeFactors
Prime factors decomposition.- Parameters:
n
- Number to factorize: must be ≥ 2.- Returns:
- the list of prime factors of
n
. - Throws:
IllegalArgumentException
- if n < 2.
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