UVA 11178 Morley定理(幾何入門）

#include<bits/stdc++.h>
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.y*p);}
Vector operator /(Vector A,double p){return Vector(A.x/p,A.y/p);}

bool operator <(const Point& a,const Point &b){
	return a.x<b.x || (a.x==b.x && a.y<b.y);
}

const double eps=1e-10;
int dcmp(double x){
	if(fabs(x)<eps) 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){          //rad正數時表示逆時針 負數時表示順時針 
	return Vector(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));
}

//計算向量的單位法線 
Vector normal(Vector A){
	double l=length(A);
	return Vector(-A.y/l,A.x/l);
}

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);
}

Point getlineintersection(Point p,Vector v,Point q,Vector w){
	Vector u=p-q;
	double t=cross(w,u)/cross(v,w);
	return p+v*t;
}


double distancetoline(Point P,Point A,Point B){
	Vector v1=B-A,v2=P-A;
	return fabs(cross(v1,v2)/length(v1));
}


Point getlineprojection(Point P,Point A,Point B){
	Vector v=A-B;
	return A+v*(dot(v,P-A)/dot(v,v));
}


int n;

Point getD(Point A,Point B,Point C){
	Vector v1=C-B;
	Vector v5=A-B;
	double a1=angle(v5,v1);
	Vector v2=rotate(v1,a1/3);
	
	Vector v3=B-C;
	double a2=angle(v3,A-C);
	Vector v4=rotate(v3,-a2/3);
	
	return getlineintersection(B,v2,C,v4);
}

int main(){
	scanf("%d",&n);
	Point A,B,C,D,E,F;
	while(n--){
		scanf("%lf %lf",&A.x,&A.y);
		scanf("%lf %lf",&B.x,&B.y);
		scanf("%lf %lf",&C.x,&C.y);
		D=getD(A,B,C);
		E=getD(B,C,A);
		F=getD(C,A,B);
		printf("%.6lf %.6lf %.6lf %.6lf %.6lf %.6lf\n",D.x,D.y,E.x,E.y,F.x,F.y);
		
	}
	
}