Class SIQS_Small
java.lang.Object
de.tilman_neumann.jml.factor.FactorAlgorithm
de.tilman_neumann.jml.factor.siqs.SIQS_Small
public class SIQS_Small extends FactorAlgorithm
Single-threaded SIQS implementation used to factor the Q(x)-rests in the trial division stage of SIQS/PSIQS.
So far, the main purpose of this class is to prevent excessive logging when GlobalFactoringOptions.ANALYZE == true and SIQS
trial division starts to use an nested SIQS to factor large Q rests. A second purpose would be to optimize
this class for the factorization of small N (say, below 100 bit), but little effort has been dedicated to that so far.
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Field Summary
Fields inherited from class de.tilman_neumann.jml.factor.FactorAlgorithm
NUM_PRIMES_FOR_31_BIT_TDIV, tdivLimit
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Constructor Summary
Constructors Constructor Description SIQS_Small(float Cmult, float Mmult, java.lang.Integer wantedQCount, SIQSPolyGenerator polyGenerator, int extraCongruences, boolean permitUnsafeUsage)
Standard constructor. -
Method Summary
Modifier and Type Method Description void
cleanUp()
java.math.BigInteger
findSingleFactor(java.math.BigInteger N)
Test the current N.java.lang.String
getName()
static void
main(java.lang.String[] args)
Stand-alone test.void
searchFactors(FactorArguments args, FactorResult result)
Try to find at least one factor of the given args.N, which is composite and odd.Methods inherited from class de.tilman_neumann.jml.factor.FactorAlgorithm
factor, factor, getDefault
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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SIQS_Small
public SIQS_Small(float Cmult, float Mmult, java.lang.Integer wantedQCount, SIQSPolyGenerator polyGenerator, int extraCongruences, boolean permitUnsafeUsage)Standard constructor.- Parameters:
Cmult
- multiplier for prime base sizeMmult
- multiplier for sieve array sizewantedQCount
- the wanted number of q whose product gives the a-parameterpolyGenerator
-extraCongruences
- the number of surplus congruences we collect to have a greater chance that the equation system solves.permitUnsafeUsage
- if true then SIQS_Small uses a sieve exploiting sun.misc.Unsafe features. This may be ~10% faster.
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Method Details
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getName
public java.lang.String getName()- Specified by:
getName
in classFactorAlgorithm
- Returns:
- The name of the algorithm, possibly including important parameters.
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searchFactors
Description copied from class:FactorAlgorithm
Try to find at least one factor of the given args.N, which is composite and odd. This is a default implementation for algorithms that will only find a single factor or none at all. For sub-algorithms that may find more factors at once this method should be overwritten appropriately.- Overrides:
searchFactors
in classFactorAlgorithm
result
- the result of the factoring attempt. Should be initialized only once by the caller to reduce overhead.
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findSingleFactor
public java.math.BigInteger findSingleFactor(java.math.BigInteger N)Test the current N.- Specified by:
findSingleFactor
in classFactorAlgorithm
- Parameters:
N
- number to be factored.- Returns:
- factor, or null if no factor was found.
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cleanUp
public void cleanUp() -
main
public static void main(java.lang.String[] args)Stand-alone test.- Parameters:
args
- ignored Some test numbers: 11111111111111111111111111 5679148659138759837165981543 11111111111111111111111111155555555555111111111111111 2900608971182010301486951469292513060638582965350239259380273225053930627446289431038392125 = 33333 * 33335 * 33337 * 33339 * 33341 * 33343 * 33345 * 33347 * 33349 * 33351 * 33353 * 33355 * 33357 * 33359 * 33361 * 33363 * 33367 * 33369 * 33369 * 33371 15841065490425479923 = 2604221509 * 6082841047
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