: Dear Sir,
: My question is that how i can write a c++ program that calculates and displays the sum of all prime numbers in a user-defined closed interval[a,b] of positive integers using both pre-defined (standard)and user-defined functions.
: Waiting for your reply.
: Thanking you,
: Md.Zulfiker HOSSAIN
I am not to advanced in c++ but this may be a solution without stdandard funtions
you get the inteval with two input statements cin << a and cin << b
then run a function that would get all of the prime numbers <= b that number, and read them into a vector
then run the same function for prime numbers <= a and read them into a different vector
then erase all of the same prime numbers < a in the first vector
then add up all of the prime numbers in the first vector