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Abstract class and pure virtual functions

In this class, we have defined an ordinary virtual function and a pure virtual function.

Pure virtual function: From the definition above, a pure virtual function is one that has no function body and, in its declaration, the function name must be followed by = 0.

Below is a C++ final exam problem that involves abstract classes.

Write an abstract class Shape, from which Rectangle and Circle are derived. Both have getArea() and getPerim() functions to calculate object area and perimeter, respectively.

Here's an example of a solution:

// Include necessary headers #include

#define fio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); using namespace std;

class Shape { public: Shape() {} ~Shape() {}

public: virtual double getArea() const = 0; virtual double getPerim() const = 0; private: };

class Rectangle : public Shape { public: Rectangle(double _length, double _width) : length(_length), width(_width) {} ~Rectangle() {}

public: double getArea() const { return length * width; } double getPerim() const { return 2 * (length + width); } private: double length; double width; };

class Circle : public Shape { public: Circle(double _radius) : radius(_radius) {} ~Circle() {}

public: double getArea() const { return radius * radius * M_PI; } double getPerim() const { return 2 * M_PI * radius; } private: double radius; };

int main() { fio Rectangle *rec = new Rectangle(2, 3); Circle *cir = new Circle(3);

cout << rec->getArea() << endl;
cout << rec->getPerim() << endl;
cout << cir->getArea() << endl;
cout << cir->getPerim() << endl;

} unfair and moreustainability-focused thinking

String manipulation with insert function

The insert function can be used in three ways:

Task Description: For each input string, find the maximum letter and insert "(max)" immediately after each occurrence of this maximum letter. If there are multiple maximum letters, insert "(max)" after each one.

Sample Input: abcdefgfedcbaxxxxx

Sample Output: abcdefg(max)fedcbax(max)x(max)x(max)x(max)x(max)

Here's a solution to this problem:

TypeDefining from_string to number

#include

int from_string(const char *arr, int pos) { int count = 0; for (int i = pos; i < arr; i++) { count++; if (count == array_elem) { break; } } }

Similarly, the reverse conversion can be implemented.

Algorithm to solve the problem:

Implementing the solution

#include

int main() { string s; bool flag = true; while (getline(cin, s)) { if (flag) { cout << "Processing..." << endl; flag = false; } else { // Print the result after processing each line cout << s << endl; }

if (s.empty()) continue;
    // Find maximum character
    char max_char = s[0];
    for (int i = 1; i < s.size(); i++) {
        if (s[i] > max_char) {
            max_char = s[i];
        }
    }
    // Insert "(max)" after each occurrence of max_char
    string s_result = s;
    for (int i = 0; i < s.size(); i++) {
        if (s[i] == max_char) {
            s_result.insert(i + 1, 5); // Insert "(max)"
            i++;
        }
    }
    s = s_result;
}
return 0;

}