I am trying to do Factorial with Recursion and BigIntegers but eclipse is complaining about the BigInteger. I know the program is supposed to be simple but it is giving me h
In addition to what @aix mentioned regarding invoking the arithmetics on BigInteger
- I can also see another issue with this code.
Your method signature is
public static int fact(BigInteger n)
This is problemantic - factorial grows fast, so you are very likely to overflow the result.
I think what you realy wanted is:
public static BigInteger fact(int n)
which makes much more sense, since the return value should probably be the BigInteger
(since it grows fast) and not the parameter, or possibly - both of them.
I believe you can't simply use arithmetic operator onto BigInteger object. Try to use their methods for arithmetic processes such as comparing, subtracting, multiplying etc.
References are given here
Java doesn't support operator overloading. So + and == can't be supported for user-defined classes with one exception that java.lang.String supports +.
BigInteger
does not support comparison using ==
and multiplication using *
. Instead, you have to call the appropriate methods of the BigInteger
class (equals() and multipy()).
Also note that there exist BigInteger.ZERO and BigInteger.ONE.
Finally, the return type of your fact
method should be BigInteger
and not int
. Whether you want the argument to be of type BigInteger
or int
is up to you.