protecteyesight的博客

依次给出ABC三个点的坐标，求从A经过B到达C，在B点向哪个方向转身。用叉积做。int main(){ int a,b,c,d,e,f,n,ans; cin>>n; for(int i=0;i<n;i++) {cin>>a>>b>>c>>d>>e>>f; ans=(e-a)*(d-b)-(f-b)*(c-a);//ans计算叉积 if(ans==0)co

struct Point//点的定义{ double x,y; Point(){} Point(double _x,double _y) { x=_x;y=_y; } double operator ^(const Point &b)const { return x*b.y-y*b.x; }};

struct point//点的定义{ double x; double y;};struct V//向量的定义{ point sstart; point eend;};double Cross(V*v1,V *v2)//叉积{ V vt1,vt2; double result=0; vt1.sstart.x=0; vt

#include using namespace std;struct Point//点的定义{ double x,y;};typedef struct line//向量定义{ Point start,end;}vector;double multi(Point p1,Point p2,Point p0){ return (p1.x-p0.x)*(p

#include #include #include #include using namespace std;struct Point{ double x,y;};Point a[1005],d;double r;double dist(Point A,Point B){ return sqrt((A.x-B.x)*(A.x-B.x)+(A.y-B.

Matt is a big fan of logo design. Recently he falls in love with logo made up by rings. The following figures are some famous examples you may know. A ring is a 2-D figure bounded by two circl