UVA 11178 Morley's Theorem 计算几何模板

题意：训练指南259页

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>

using namespace std;

const double eps=1e-8;

int dcmp(double x)
{
    if(fabs(x)<eps) return 0; else return (x<0)?-1:1;
}

struct Point
{
    double x,y;
    Point(double _x=0,double _y=0):x(_x),y(_y){}
};

Point operator+(Point A,Point B) {return Point(A.x+B.x,A.y+B.y);}
Point operator-(Point A,Point B) {return Point(A.x-B.x,A.y-B.y);}
Point operator*(Point A,double p) {return Point(A.x*p,A.y*p);}
Point operator/(Point A,double p) {return Point(A.x/p,A.y/p);}

Point A,B,C;

double Dot(Point A,Point B) {return A.x*B.x+A.y*B.y;}
double Length(Point A) {return sqrt(Dot(A,A));}
double Angle(Point A,Point B) {return acos(Dot(A,B)/Length(A)/Length(B));}
double angle(Point v) {return atan2(v.y,v.x);}
double Cross(Point A,Point B) {return A.x*B.y-A.y*B.x;}

Point Rotate(Point A,double rad)
{
    return Point(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));
}

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

Point getD(Point A,Point B,Point C)
{
    Point v1=C-B;
    double a1=Angle(A-B,v1);
    v1=Rotate(v1,a1/3);

    Point v2=B-C;
    double a2=Angle(A-C,v2);
    v2=Rotate(v2,-a2/3);

    return GetLineIntersection(B,v1,C,v2);
}

void read(Point &a)
{
    scanf("%lf %lf",&a.x,&a.y);
}
int main()
{
    int cas;
    scanf("%d",&cas);
    while(cas--)
    {
        Point a,b,c,d,e,f;
        read(a);
        read(b);
        read(c);
        d=getD(a,b,c);
        e=getD(b,c,a);
        f=getD(c,a,b);
        printf("%.6f %.6f %.6f %.6f %.6f %.6f
",d.x,d.y,e.x,e.y,f.x,f.y);
    }
    return 0;
}