foo.cpp: In function 'int main()':
foo.cpp:39:30: error: lvalue required as unary '&' operand
   scanf("%lf%lf", &a[i].real(), &b[n-i-1].real());
                              ^
foo.cpp:39:48: error: lvalue required as unary '&' operand
   scanf("%lf%lf", &a[i].real(), &b[n-i-1].real());
                                                ^