Multiplication of very long integers

Question

Is there an algorithm for accurately multiplying two arbitrarily long integers together? The language I am working with is limited to 64-bit unsigned integer length (maximum int

Answer 1

Yes, you do it using a datatype that is effectively a string of digits (just like a normal 'string' is a string of characters). How you do this is highly language-dependent. For instance, Java uses BigDecimal. What language are you using?