有如下程序： #include ＜iostream＞ using namespace std class Part{ public: Part(int x=0):val(x) { cout＜＜val } ～Part() { cout＜＜val } private: int val } class Whole { public: Whole(int x, int y, int z=0):p2(x),p1 (y),val(z) { cout＜＜val } ～whole() { cout＜＜val private: Part p1,p2 int val } int main() { Whole obj (1,2,3) return 0 }程序的输出结果是