I want to set f(x,y)=g(x,y)+g(-x,y) this equation 2D has to be symmetry. I don’t know how to write the loop for x and -x. Does anyone know how to write the loops for this equation?

— C++

— Is this a loop?

— This is a equation

— We can write for(i=0; i<2*n ; i++) this is for +x my problem is -x

— If x=i then is not -x=-i?

— I think we need to set new index like newi depends on i

— For(i=0,j=0; i<2*n; i++,j--)

— Oh

— Is that working?

— I mean i and j in same loop or we should separate them