One of the C++ programmers problems is to work with integers greater than
2^64-1 (we can save
unsigned long long int). So I want to share the best Bignum implementation I have ever seen (Link) with CodeForces Community.
Its specifications are as follows:
It is able to work with Standard Input/Output streams.
It can cast data to
It uses fast multiplication.
source.(but I have edited that and added
UPD1 (September 2016): bug in
void operator=(long long v) is now fixed. Thanks to AmSen.