这个C++程序怎么分析啊 谢谢~~
#include <iostream.h>#include <stdio.h>class Base {public: int m_a,m_b; Base (int a=3,int b=5):m_a(a),m_b(b){} int func_a(){return m_a - m_b;} virtual int func_b(){return m_a + m_b;}};class Derived :public Base {public: Derived (int a=4,int b=7):Base(a,b){} virtual int func_a(){return m_b + m_a;} int func_b(){return m_b - m_a;}};int main(){ Base *aa,*bb; aa = new Base(4,7); bb = new Derived(3,5); printf("%d %d %d %d\n",aa->func_a(),aa->func_b(),bb->func_a(),bb->func_b()); delete aa; delete bb; return 0;}