Graham凸包。

Signed-off-by: CyberZHG <CyberZHG@gmail.com>
旋转卡壳。

Signed-off-by: CyberZHG <CyberZHG@gmail.com>
计算几何二维部分。

Signed-off-by: CyberZHG <CyberZHG@gmail.com>