隔断继承的疑惑-待问

  #include<iostream>
  2 #include<string>
  3 using namespace std;
  4 class parent{
  5 protected:
  6         int m_a;
  7         int m_b;
  8 public:
  9         int m_c;
 10         void set(int a,int b,int c){
 11                 m_a = a;
 12                 m_b = b;
 13                 m_c = c;
 14         }
 15 };
 16 class child_A:public parent{
 17 public:
 18         void print(){
 19                 cout << "m_a=" << m_a << endl;
 20                 cout << "m_b=" << m_b << endl;
 21                 cout << "m_c=" << m_c << endl;
 22         }
 23 };
 24 class child_B:protected parent{
 25 public:
 26         void print(){
 27                 cout << "m_a=" << m_a << endl;
 28                 cout << "m_b=" << m_b << endl;
 29                 cout << "m_c=" << m_c << endl;
30         }
 31 };
 32 class child_C:private parent{
 33 public:
 34         void print(){
 35                 cout << "m_a=" << m_a << endl;
 36                 cout << "m_b=" << m_b << endl;
 37                 cout << "m_c=" << m_c << endl;
 38         }
 39 
 40 };
 41 class child_D:public child_C{
 42 };
 43 int main(){
 44         //child_A a;//public继承
 45         //child_B b;//protected 继承
 46         //child_C c;//private继承
 47         //a.m_c = 100;//100
 48         //b.m_c = 100;//100
 49         //c.m_c = 100;
 50         //a.print();
 51         //b.print();
 52         //c.print();
 53         //cout << endl;
 54         //a.set(1,1,1);
 55         //b.set(2,2,2);
 56         //c.set(3,3,3);
57         child_D d;
 58         d.print();
 59         d.set(1,2,3);
 60         return 0;
 61 }