#include <iostream>

using namespace std;

int main() {

    float radius, perimeter;

    const float pi = 3.14159;

    cout << "Enter the radius of the circle: ";

    cin >> radius;

    perimeter = 2 * pi * radius;

    cout << "The perimeter (circumference) of the circle is: " << perimeter;

    return 0;

}

#include <iostream>

using namespace std;

class Division {

private:

    float num1, num2;

public:

    // Constructor

    Division(float a, float b) {

        num1 = a;

        num2 = b;

    }

    // Function to perform division

    void divide() {

        if (num2 == 0) {

            cout << "Error: Division by zero is not allowed." << endl;

        } else {

            float result = num1 / num2;

            cout << "Result of division: " << result << endl;

        }

    }

};

int main() {

    float a, b;

    cout << "Enter two numbers: ";

    cin >> a >> b;

    // Creating object and calling constructor

    Division d(a, b);

    // Calling divide function

    d.divide();

    return 0;

}

#include <iostream>

using namespace std;

class Counter {

public:

    static int value;  // static variable

    // Function to decrement the variable

    void decrement() {

        value--;

    }

    // Function to display value

    void display() {

        cout << "Value: " << value << endl;

    }

};

// Initialize static variable

int Counter::value = 10;

int main() {

    Counter obj1, obj2;

    obj1.display();   // Initial value

    obj1.decrement(); // Decrement

    obj2.display();   // Updated value (shared)

    return 0;

}

#include <iostream>

using namespace std;

class Shape {

public:

    // Square

    void area(float side) {

        cout << "Area of Square: " << side * side << endl;

    }

    void perimeter(float side, int) {  // dummy int for overloading

        cout << "Perimeter of Square: " << 4 * side << endl;

    }

    // Rectangle

    void area(float length, float breadth) {

        cout << "Area of Rectangle: " << length * breadth << endl;

    }

    void perimeter(float length, float breadth, int) {

        cout << "Perimeter of Rectangle: " << 2 * (length + breadth) << endl;

    }

    // Circle

    void area(double radius) {

        cout << "Area of Circle: " << 3.14159 * radius * radius << endl;

    }

    void perimeter(double radius, char) {  // dummy char for overloading

        cout << "Perimeter of Circle: " << 2 * 3.14159 * radius << endl;

    }

};

int main() {

    Shape s;

    // Square

    s.area(5);

    s.perimeter(5, 0);

    // Rectangle

    s.area(4, 6);

    s.perimeter(4, 6, 0);

    // Circle

    s.area(3.0);

    s.perimeter(3.0, 'a');

    return 0;

}

#include <iostream>

using namespace std;

class Rectangle {

private:

    float length, breadth;

public:

    // Function to input values

    void getData() {

        cout << "Enter length and breadth: ";

        cin >> length >> breadth;

    }

    // Function to calculate area

    void area() {

        cout << "Area of rectangle: " << length * breadth << endl;

    }

    // Function to calculate perimeter

    void perimeter() {

        cout << "Perimeter of rectangle: " << 2 * (length + breadth) << endl;

    }

};

int main() {

    Rectangle r;

    r.getData();

    r.area();

    r.perimeter();

    return 0;

}

#include <iostream>

using namespace std;

// Base class

class Shape {

public:

    virtual void perimeter() {

        cout << "Calculating perimeter..." << endl;

    }

};

// Derived class for Rectangle

class Rectangle : public Shape {

private:

    float length, breadth;

public:

    Rectangle(float l, float b) {

        length = l;

        breadth = b;

    }

    void perimeter() {

        cout << "Perimeter of Rectangle: " << 2 * (length + breadth) << endl;

    }

};

// Derived class for Square

class Square : public Shape {

private:

    float side;

public:

    Square(float s) {

        side = s;

    }

    void perimeter() {

        cout << "Perimeter of Square: " << 4 * side << endl;

    }

};

// Derived class for Triangle

class Triangle : public Shape {

private:

    float a, b, c;

public:

    Triangle(float x, float y, float z) {

        a = x;

        b = y;

        c = z;

    }

    void perimeter() {

        cout << "Perimeter of Triangle: " << a + b + c << endl;

    }

};

int main() {

    Shape* s;

    Rectangle r(4, 5);

    Square sq(3);

    Triangle t(3, 4, 5);

    s = &r;

    s->perimeter();

    s = &sq;

    s->perimeter();

    s = &t;

    s->perimeter();

    return 0;

}

#include <iostream>

using namespace std;

// Abstract base class

class Student {

protected:

    string name;

    int roll_no;

public:

    // Pure virtual function

    virtual void Info() = 0;

};

// Derived class Marks

class Marks : public Student {

protected:

    float m1, m2, m3;

public:

    void Info() {

        cout << "Enter Name: ";

        cin >> name;

        cout << "Enter Roll Number: ";

        cin >> roll_no;

        cout << "Enter marks of 3 subjects: ";

        cin >> m1 >> m2 >> m3;

    }

    float getMarksTotal() {

        return m1 + m2 + m3;

    }

};

// Derived class Sports

class Sports : public Student {

protected:

    float sportsMarks;

public:

    void Info() {

        cout << "Enter Sports Marks: ";

        cin >> sportsMarks;

    }

    float getSportsMarks() {

        return sportsMarks;

    }

};

// Derived class Result (Multiple Inheritance)

class Result : public Marks, public Sports {

public:

    void display() {

        float total = getMarksTotal() + getSportsMarks();

        cout << "\n--- Student Result ---" << endl;

        cout << "Name: " << name << endl;

        cout << "Roll Number: " << roll_no << endl;

        cout << "Total Marks: " << total << endl;

    }

};

int main() {

    Result r;

    r.Marks::Info();   // Input name, roll no, subject marks

    r.Sports::Info();  // Input sports marks

    r.display();

    return 0;

}

#include <iostream>

using namespace std;

int main() {

    int num;

    cout << "Enter a number: ";

    cin >> num;

    int square = num * num;

    int cube = num * num * num;

    cout << "Square of the number: " << square << endl;

    cout << "Cube of the number: " << cube << endl;

    return 0;

}

#include <iostream>

#include <stdexcept>  // For standard exceptions

using namespace std;

int main() {

    int age;

    cout << "Enter employee age: ";

    cin >> age;

    try {

        if (age < 15) {

            throw runtime_error("Age is less than 15. Invalid age!");

        }

        cout << "Employee age: " << age << endl;

    }

    catch (runtime_error &e) {

        cout << "Exception caught: " << e.what() << endl;

    }

    return 0;

}