void add_element(const int& element)
{
        if (capacity < newSize) {
            newBuffer[capacity] = element;
        }
        else if (capacity >= newSize) {
            newSize = newSize * 2;
            int* newBuffer = new int[newSize];
            memcpy(newBuffer, buffer, sizeof(buffer)*capacity);
            newBuffer[capacity] = element;
            //delete[] buffer;
            //buffer = newBuffer;
        }
        delete[] buffer;
        buffer = newBuffer;
        capacity = capacity + 1;
}