Explore OOP in C++ to write cleaner, modular, and scalable code. Learn classes in C++, data hiding, encapsulation, abstraction, inheritance, and polymorphism in C++.

Become  a C++ Programmer

This module aims to teach us how to write cleaner, more modular, and scalable code in C++ by providing an understanding of OOP in C++. We'll start with the basics of object-oriented programming and build up to advanced concepts such as inheritance, data hiding, and polymorphism. Along the way, we'll explore how each concept applies to C++ and how various C++ features facilitate OOP.

Object-Oriented Programming in C++

## Problem Statement
In this challenge, you are given a class called `DynamicArray` which implements a dynamic array of integers that can grow in size. 

This class has the following functions:
- `void append(int value)`: Adds a new value at the end of the array.
- `int get(int index)`: Returns the value at the given index.
- `int length()`: Returns the current size of the array. 
- `void resize()`: Resizes the array when the maximum capacity is reached. The growth factor is two, therefore, it will each time double the capacity of the array. 


Your task is to write a derived class called `DynamicArrayWithStats` which will implement the following functions:
- `int max()`: Returns the maximum element in the dynamic array.
- `int min()`: Returns the minimum element present in the dynamic array.
- `int mean()`: Finds the mean value from the elements in the array and returns it. 

### Input
The input will be an integer and it will be given using the `append()` function. The `get()` function will be used to print the values in the dynamic array. Then, all functions of the `DynamicArrayWithStats` class will be called. 

### Sample Input
We want to execute the following instructions:
``` C++
    DynamicArrayWithStats arr = DynamicArrayWithStats();
    arr.append(2);
    arr.append(6);
    arr.append(4);
    arr.append(1);
    arr.append(3);

    cout << "Array: ";
    for(int i = 0; i < arr.length(); i++){
        cout << arr.get(i) << " ";
    }
    cout << endl;
    
    cout << "Max: " << arr.max() << endl;
    cout << "Min: " << arr.min() << endl;
    cout << "Mean: " << arr.mean() << endl;
```

### Expected Output
The following is the correct output:
```txt
Array: 2 6 4 1 3 
Max: 6
Min: 1
Mean: 3
```


# Problem Statement
In this challenge, you are given a class called `DynamicArray` which implements a dynamic array of integers that can grow in size. 

This class has the following functions:
- `void append(int value)`: Adds a new value at the end of the array.
- `int get(int index)`: Returns the value at the given index.
- `int length()`: Returns the current size of the array. 
- `void resize()`: Resizes the array when the maximum capacity is reached. The growth factor is two, therefore, it will each time double the capacity of the array. 


Your task is to write a derived class called `DynamicArrayWithStats` which will implement the following functions:
- `int max()`: Returns the maximum element in the dynamic array.
- `int min()`: Returns the minimum element present in the dynamic array.
- `int mean()`: Finds the mean value from the elements in the array and returns it. 

## Input
The input will be an integer and it will be given using the `append()` function. The `get()` function will be used to print the values in the dynamic array. Then, all functions of the `DynamicArrayWithStats` class will be called. 

## Sample Input
We want to execute the following instructions:
``` C++
    DynamicArrayWithStats arr = DynamicArrayWithStats();
    arr.append(2);
    arr.append(6);
    arr.append(4);
    arr.append(1);
    arr.append(3);

    cout << "Array: ";
    for(int i = 0; i < arr.length(); i++){
        cout << arr.get(i) << " ";
    }
    cout << endl;
    
    cout << "Max: " << arr.max() << endl;
    cout << "Min: " << arr.min() << endl;
    cout << "Mean: " << arr.mean() << endl;
```

## Expected Output
The following is the correct output:
```txt
Array: 2 6 4 1 3 
Max: 6
Min: 1
Mean: 3
```


In this exercise, you have to implement a derived class that will calculate the min, max and the mean of the data set given in the dynamic array. 

Introduction

Classes

Data Hiding

Inheritance

Polymorphism

Conclusion

Challenge 4: Implement Derived Class to Calculate Min/Max/Mean

Problem Statement