有如下程序： #include ＜iostream＞ using namespace std; class ONE { public: virtual void f() { cout ＜＜ "1"; } }; class TWO: public ONE { public: TWO() { cout ＜＜ "2"; } }; class THREE: public TWO { public: virtual void f() {TWO::f(); cout ＜＜ "3"; } }; int main() { ONE aa, *p; TWO bb; THREE cc; p=&cc; P-＞f(); return 0; } 执行上面程序的输出是 【11】 。