BSD 2-clause “Simplified” License

mvn clean install

mvn test

Factoring a BigInteger The following uses the Pollard-rho method of factorization:

ArrayList<BigInteger> list = Factorizor.factor(new BigInteger("909077759200010102032010201"), Factorizor.FactorMethod.RHO);

will return

967, 9819889267, 95734388625509

Pollard P-1 method is also implemented:

ArrayList<BigInteger> list2 = Factorizor.factor(new BigInteger("425624900000909000001111317911"), Factorizor.FactorMethod.PMO);

returns

571, 62818373, 11865997022428766417

Factorizor also includes a P+1 factorization algorithm implementation.

Euler Totient of a BigInteger

Euler totient is defined Totient

BigInteger tot = Totient.totient(new BigInteger("425624"));

returns

209920

Calculating number of primes less than a given float (or BigDecimal)

int q = PrimeCount.pi(1000000f);

returns

78498

This uses the Meissel formula to calculate pi(x). It will probably choke on values much larger than 10 million though.

Calculate Lexicographically ordered permutations of list of objects (which implement Comparable)

ArrayList<Character[]> permutations = PermutationsGeneric.getLexicographicPermutations(new Character[]{'a', 'b', 'c'});

This returns six permutations:

	```
	{'a','b','c'}
	{'a','c','b'}
	{'b','a','c'}
	{'b','c','a'}
	{'c','a','b'}
	{'c','b','a'}
	```