爆米

向量叉积有甚多应用，包括求三角形面积，判断线段相交，求多边形面积，判断多边形凹凸性，而且不需要推大量公式，误差较小，非常实用，下面是代码//向量叉积的应用#include #define EPS 1e-10using namespace std;struct point{ double x, y; point(int x = 0, int y = 0) : x

The figure shown on the left is left-right symmetric as it is possible to fold the sheet of paper along a vertical line, drawn as a dashed line, and to cut the figure into two identical halves. The fi