#include <bits/stdc++.h> #define ll long long #define f(i,a,b) for(int i=a;i<=b;i++) #define scan(i) scanf("%d",&i) #define pf printf using namespace std; const double eps=1e-10; const double PI=acos(-1.0); using namespace std; struct Point{ double x; double y; Point(double x=0,double y=0):x(x),y(y){} void operator<<(Point &A) {cout<<A.x<<' '<<A.y<<endl;} bool operator!=(Point &A) {if(fabs(A.x-x)>eps||fabs(A.y-y)>eps) return true;return false;} }; int dcmp(double x) {return (x>eps)-(x<-eps); } int sgn(double x) {return (x>eps)-(x<-eps); } 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.y*p); } Vector operator /(Vector A,double p) {return Vector(A.x/p,A.y/p);} ostream &operator<<(ostream & out,Point & P) { out<<P.x<<' '<<P.y<<endl; return out;} bool operator< (const Point &A,const Point &B) { return dcmp(A.x-B.x)<0||(dcmp(A.x-B.x)==0&&dcmp(A.y-B.y)<0); } 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 Cross(Vector A,Vector B) {return A.x*B.y-B.x*A.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));} double Area2(Point A,Point B,Point C ) {return fabs(Cross(B-A, C-A));} Vector Rotate(Vector A,double rad) { return Vector(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));} Vector Normal(Vector A) {double L=Length(A);return Vector(-A.y/L,A.x/L);} Point GetLineIntersection(Point P,Vector v,Point Q,Vector w){ if(v.x*w.y==v.y*w.x) return Point(5201314,5201314); Vector u=P-Q; double t=Cross(w, u)/Cross(v,w); return P+v*t; }//输入两个点斜式方程输出交点 bool OnSegment(Point P,Point A,Point B){ return dcmp(Cross(P-A, P-B))==0&&dcmp(Dot(P-A,P-B))<=0; }//输入三个点,判断P是否在线段AB上