天翼之城的博客

This way 题意： 二维明面上有n个点，设f§为绝对包含点p的n个点中的4点集合的个数，问你所有的f§之和是多少 题解： 看到平面几何我就跪了，，但是看题解这也不是一道很难的题目。对于一个点，如果有4个点五论怎么连线都无法包含这个点，那么这4个点一定在这个点的一侧，也就是说这些点和这个点的夹角不会超过180度 那么我们枚举红点的时候，对于这个点建立坐标系，也就是将其他点先算出相对于这个点的...

下载LOFTER我的照片书 | Problem Description Chiaki has 3n points p1,p2,…,p3n. It is guaranteed that no three points are collinear. Chiaki would like to construct n disjoint triangles where each vertex com...

Problem Description After trying hard for many years, Little Q has finally received an astronaut license. To celebrate the fact, he intends to buy himself a spaceship and make an interstellar travel....