int main()
{
    int *ptr;
    int n = 20;
    ptr = new int[n];
    ptr[5] = 7;
    ptr[6] = 9;
    cout << ptr[5] << " " << ptr[6] << "\n";
    delete[] ptr;
    cout << ptr[5] << " " << ptr[6];
}

7 9
-1785358955 -1785358955