在 Graham 扫描中检查禁止左转
Checking for a nonleft turn in Graham's scan
根据 Cormen "Introduction to Algorithms" 对格雷厄姆扫描算法的描述，我发现了以下注释：
By checking for a nonleft turn, rather than just a right turn, this test precludes the possibility of a straight angle at a vertex of the resulting convex hull. We want no straight angles, since no vertex of a convex polygon may be a convex combination of other vertices of the polygon.
有人能解释一下吗，为什么我们要在生成的凸包的顶点处跳过直角？不清楚为什么
no vertex of a convex polygon may be a convex combination of other vertices of the polygon
这是真的，因为根据定义，凸包是包含多边形的最小凸点集。
根据 Cormen "Introduction to Algorithms" 对格雷厄姆扫描算法的描述，我发现了以下注释：
By checking for a nonleft turn, rather than just a right turn, this test precludes the possibility of a straight angle at a vertex of the resulting convex hull. We want no straight angles, since no vertex of a convex polygon may be a convex combination of other vertices of the polygon.
有人能解释一下吗，为什么我们要在生成的凸包的顶点处跳过直角？不清楚为什么
no vertex of a convex polygon may be a convex combination of other vertices of the polygon
这是真的，因为根据定义，凸包是包含多边形的最小凸点集。