图片数组泛洪算法，8邻域泛洪算法

递归函数

void flood_array8(int x, int y, int width, int height,unsigned char * buf)
{
if(x >= 0 && x < height && y >= 0 && y < width && buf[x * width + y] == 4)
{
num+=1;
buf[x * width + y] = 99;//标记被泛洪的像素
flood_array8(x + 1, y,     width, height, buf);
flood_array8(x - 1, y,     width, height, buf);
flood_array8(x,     y + 1, width, height, buf);
flood_array8(x,     y - 1, width, height, buf);
flood_array8(x + 1, y + 1, width, height, buf);
flood_array8(x - 1, y - 1, width, height, buf);
flood_array8(x - 1, y + 1, width, height, buf);
flood_array8(x + 1, y - 1, width, height, buf);
}
}