请说出下面程序中【代码1】和【代码2】的输出结果，以空格隔开。 interface A { double f(double x, double y); } class B implements A { public double f(double x, double y) { return x * y; } int g(int a, int b) { return a + b; } } public class Main { public static void main(String args]) { A a = new B(); System.out.println(a.f(3, 5)); //【代码1】 B b = (B) a; System.out.println(b.g(3, 5)); //【代码2】 } }