DYNAMIC ARRAY

// DYNAMIC ARRAYS
#include <iostream>
#include <limits>
using namespace std;

// Function Prototype
void insert(int *arr, unsigned int &size, unsigned int &allocted_size);

// Driver Code
int main()
{
    unsigned int size;
    unsigned int allocated_size = 0;
    cout << "Enter the size of the array : ";
    while (!(cin >> size))
    {
        cin.clear();
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cout << "Please enter a valid input : ";
    }

    // Dynamic Memory Allocation
    int *arr = new int[size];
    cout << "An array of size " << size << " has been created successfully." << endl;

    // Function Calls
    insert(arr, size, allocated_size);
    insert(arr, size, allocated_size);
    insert(arr, size, allocated_size);

    return 0;
}

// Insert Function : This function takes the integer from the user and pushes in into the array and if the space is full then it expands the array and then inserts the value
void insert(int *arr, unsigned int &size, unsigned int &allocted_size)
{
    // User Input
    int value;
    cout << "Enter the value to be inserted in the array : ";
    while (!(cin >> value))
    {
        cin.clear();
        cin.ignore(numeric_limits<streamsize>::max(), '\n');
        cout << "Please enter a valid int input : ";
    }

    // If the allocated size is less then the actual size of the array then push the element into the array and increment the allocated_size value by one
    if (allocted_size < size)
    {
        *(arr + allocted_size) = value;
        cout << "Successfully inserted " << value << " at index " << allocted_size << endl;
        allocted_size++;
    }

    // If the allocated size is equal to or more than then the actual size of the array then expand the array and push the element into the array
    else
    {
        size = size + 1;
        int *newarr = new int[size];

        // copying the elements of old array to newly created array
        for (size_t i = 0; i < size; i++)
        {
            *(newarr + i) = *(arr + i);
        }

        // pushing the element
        *(newarr + allocted_size) = value;
        cout << "Successfully expanded the array and inserted " << value << " at index " << allocted_size << endl;
        allocted_size++;

        // deallocating the space of new array
        delete[] arr;

        // pointing the old array pointer to the new array
        arr = newarr;
    }

    // printing all the elements present int the array
    for (size_t i = 0; i < allocted_size; i++)
    {
        cout << *(arr + i) << " is at index " << i << endl;
    }
}