第2题

bool c[max_size][max_size] = {false};
void draw(int size, int x, int y)
{
    if (size == 1)
    {
        c[x][y] = true;
    }
    else
    {
        int half = size / 2;
        draw(half, x + half, y);
        draw(half, x, y + half);
        draw(half, x + half, y + half);
    }
}
void print(int n)
{
    int length = 1 << n;
    draw(length, 0, 0);
    for (int x = 0; x < length; ++x)
    {
        for (int y = 0; y < length; ++y)
        {
            if (c[x][y])
                std::cout << '*';
            else
                std::cout << '.';
        }
        std::cout << "\n";
    }
}

程序输出的星号总数是（ ）。

{{ select(1) }}

• $n$
• $2^n$
• $3^n$
• $4^n$