/*

10. Complete the following function that adds up all the positive values in an

integer vector.For example, if vector vec contains the

elements 3, -3, 5, 2, 1, and 2, the call sum_positive(vec)

would evaluate to 12, since 3 + 5 + 2 + 2 = 12. The function returns zero

if the vector is empty.The function does not affect the contents of the vector.

*/