在c++中将多级继承转换为层次继承

Question

当我试图转换它时，类结果无法从类标记中获取数据，即使我公开了标记的数据变量，我也不知道为什么。我还在结果中声明了一个类标记的对象，然后试图访问它，但再次失败。我是编码新手，所以不正确地了解所有语法。你的帮助将非常有用

#include <string.h>
#include <iostream>
using namespace std;
class student {
private:
int rl;
char nm[20];
public:
void read();
void display();
};
class marks : public student {
protected:
int s1;
int s2;
int s3;
public:
void getmarks();
void putmarks();
};
class result : public marks {
private:
int t;
float p;
char div[10];
public:
void process();
void printresult();
};
void student::read() {
cout << "enter Roll no and Name " << endl;
cin >> rl >> nm;
}
void student::display() {
cout << "Roll NO:" << rl << endl;
cout << "name : " << nm << endl;
}
void marks ::getmarks() {
cout << "enter three subject marks  " << endl;
cin >> s1 >> s2 >> s3;
}
void marks ::putmarks() {
cout << "subject 1:" << s1 << endl;
cout << "subject 2 :" << s2 << endl;
cout << "subject 3:" << s3 << endl;
}
void result::process() {
t = s1 + s2 + s3;
p = t / 3.0;
p >= 60   ? strcpy(div, "first")
: p >= 50 ? strcpy(div, "second")
: strcpy(div, "third");
}
void result::printresult() {
cout << "total = " << t << endl;
cout << "per  = " << p << "%" << endl;
cout << "div = " << div << endl;
}
int main(){
result x;
x.read();
x.getmarks();
x.process();
x.display();
x.putmarks();
x.printresult();
}

Answer 1

#include<iostream>
#include<string.h>
using namespace std;
class marks  // parent class
{
protected:
int s1;
int s2;
int s3;
public:
void getmarks();
void putmarks();
};
class student : public marks     // child class
{
private:
int rl;
char nm[20];
public:
void read();
void display();
};
class result : public marks// child class
{
private:
int t;
float p;
char div[10];
public:
void process();
void printresult();
};
void student::read()
{
cout<<"enter Roll no and Name "<<endl;
cin>>rl>>nm;
}
void student:: display()
{
cout <<"Roll NO:"<<rl<<endl;
cout<<"name : "<<nm<<endl;
}
void marks ::getmarks()
{
cout<<"enter three subject marks  "<<endl;
cin>>s1>>s2>>s3;
}
void marks ::putmarks()
{
cout <<"subject 1:"<<s1<<endl;
cout<<"subject 2 :"<<s2<<endl;
cout <<"subject 3:"<<s3<<endl;
}

void result::process()
{
t= s1+s2+s3;
p = t/3.0;
p>=60?strcpy(div,"first"):p>=50?strcpy(div, "second"): strcpy(div,"third");
}

void result::printresult()
{
cout<<"total = "<<t<<endl;
cout<<"per  = "<<p<<"%"<<endl;
cout<<"div = "<<div<<endl;
}
int main()
{
result x;
student y;

y.read();
x.getmarks();
x.process();
y.display();
x.putmarks();
x.printresult();

}