C++ - unsigned long long int comparison

Hey all,

I have two unsigned long long int variables that i want to compare (such as >=, == etc) and occasionally want to apply arithmatic to (simple - operations mainly).

For example if i have two unsigned long long int variables:

a = 3316757944182080000

b = 1284800371338750000

and i want to subtract b from a (such as: c = a -b) i end up getting rubbish data in c:

that is c prints as (1.64148E+19) where c should actually equal (2.03196E+18).

any ideas?

thanks.