RosettaCodeData/Task/Prime-decomposition/Java/prime-decomposition-2.java

13 lines
549 B
Java

public static List<BigInteger> primeFactorBig(BigInteger a){
List<BigInteger> ans = new LinkedList<BigInteger>();
//loop until we test the number itself or the number is 1
for (BigInteger i = BigInteger.valueOf(2); i.compareTo(a) <= 0 && !a.equals(BigInteger.ONE);
i = i.add(BigInteger.ONE)){
while (a.remainder(i).equals(BigInteger.ZERO) && prime(i)) { //if we have a prime factor
ans.add(i); //put it in the list
a = a.divide(i); //factor it out of the number
}
}
return ans;
}