计算几何 《模板》

#include<iostream>#include<cstdio>#include<string>#include<algorithm># include<cmath>using namespace std;struct point{    double x,y;    point(double x=0,double y=0):x(x),y(y) {}};typedef point Vector;Vector operator +(Vector A,Vector B){    return  Vector(A.x+B.x,A.y+B.y);}Vector operator -(Vector A,Vector B){    return Vector(A.x-B.x,A.y-B.y);}Vector operator *(Vector A,double p){    return Vector(A.x*p, A.x*p);}Vector operator /(Vector A,double p){    return Vector(A.x/p, A.x/p);}const int esp=1e-10;bool operator <(const point& a,const point& b){    return a.x<b.x||(a.x==b.x && a.y<b.y);}int dcmp(double x){    if(fabs(x)<esp) return 0;    else        return x<0?-1:1;}bool operator ==(const point& a,const point& b){    return dcmp(a.x-b.x)==0 && dcmp(a.y-b.y)==0;}double Dot(Vector A, Vector B){    return A.x*B.x+A.y*B.y;}double Length(Vector A){    return sqrt(Dot(A,A));}double Angle(Vector A, Vector B){    return acos(Dot(A,B))/Length(A)/Length(B);}Vector Rotate (Vector A,double rad){    return Vector(A.x*cos(rad)-A.y*sin(rad), A.x*sin(rad)+A.y*cos(rad));}double cross(Vector A, Vector B){    return A.x*B.y-A.y*B.x;}double Area2(point A, point B, point C){    return cross(B-A, C-A);}int main(){    return 0;}