im programming in C++

Write a program called sumfact.c which reads an integer n from the user and sums the integers from 0! to n! if n is positive. If n is negative, the sum is computed . if n is zero, the result is assumed 1.

The output should look, like so:

The sum of the factorials from 0! to 4! is 34 The sum of the factorials from 1/(0!) to 1/(3!) is 2.666667 0! = 1 

0 ! + + + .....+ 1! n