Define the classes according to the class hierarchy in the figure . class Student store the name and roll no. of student . class Marks store the marks in three subjects . class Result store the total marks of a student. Take the input for 5 student . Find the average and display. Include all the constructor.
Objective
Write a C++ program to demonstrate Multi-Level Inheritance using Student, Marks, and Result classes.
Algorithm / Approach
- Create a base
class Studentto hold name and roll number. - Create a
class Marksthat inherits fromStudent(public Student). - Create a
class Resultthat inherits fromMarks(public Marks). - Include a default constructor in every class that prints a message.
- In
main(), create an array of 5Resultobjects and calculate their totals.
main.cpp
#include<iostream>
using namespace std;
class Student {
public:
string name;
int roll;
Student() {
cout<<"Default Const of Student\n";
}
};
class Marks : public Student {
public :
int m1,m2,m3;
Marks(){
cout<<"Default Const of Marks\n";
}
};
class Result : public Marks {
public:
int total;
float per;
Result() {
cout<<"Const. of Result "<< endl;
}
void input(){
cout<<"Enter name of Student ";
getline(cin,name);
cout<<"Enter the roll no. ";
cin>>roll;
cout<<"Enter Marks of 3 subjects ";
cin>>m1>>m2>>m3;
cin.ignore(1,'\n');
}
void display() {
total = m1+m2+m3;
per = (m1+m2+m3)/3.0;
cout<< name<<"\t"<< roll<<"\t";
cout<< total<<"\t"<< per<< endl;
}
};
int main() {
Result s[5];
for(int i = 0; i<5; i++) {
s[i].input();
}
for(int i = 0; i<5; i++) {
s[i].display();
}
return 0;
}Expected Output
Default Const of Student Default Const of Marks Const. of Result Default Const of Student Default Const of Marks Const. of Result Default Const of Student Default Const of Marks Const. of Result Default Const of Student Default Const of Marks Const. of Result Default Const of Student Default Const of Marks Const. of Result Enter name of Student Alok Enter the roll no. 12 Enter Marks of 3 subjects 90 90 90 Enter name of Student Deepak Enter the roll no. 23 Enter Marks of 3 subjects 85 85 85 Enter name of Student Ayan Enter the roll no. 34 Enter Marks of 3 subjects 99 99 99 Enter name of Student Dan Enter the roll no. 67 Enter Marks of 3 subjects 87 78 65 Enter name of Student Dan Enter the roll no. 56 Enter Marks of 3 subjects 50 50 50 Alok 12 270 90 Deepak 23 255 85 Ayan 34 297 99 Dan 67 230 76.6667 Dan 56 150 50
Explanation of the Program
- Multi-Level Inheritance creates a "grandparent → parent → child" relationship.
- When you create an object of the grandchild class (
Result), C++ automatically calls the constructors from the top of the family tree downwards. It builds theStudentbase first, then theMarksextension, and finally theResultextension.
Complexity
Time Complexity
O(n) - Where n is the number of students (5).
Space Complexity
O(n)
