11178 - Morley's Theorem【几何】

不涉及什么算法，只是简单的套用模板进行计算。

如果一个向量进行逆时针旋转，那么可以使用定义的函数 Rotate(v,rad)进行计算。

但是如果进行顺时针旋转，那么需要将rad改为-rad，也就是Rotate(v,-rad)进行计算。

精度的控制为 1e-10;

1411224311178Morley's TheoremAcceptedC++0.0552014-08-29 11:09:31

#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#include<cmath>#include<vector>#include<queue>#include<map>#include<set>using namespace std;#define INF 1 << 30#define eps 1e-10#define  Vector Point/*=============================================*/double dcmp(double x){    if(fabs(x) < eps)        return 0;    else        return x < 0 ? -1 : 1;}struct Point{    double x;    double y;Point(double a = 0,double b = 0): x(a),y(b) {};friend bool operator < (Point p,Point q){        if(p.x != q.y)                return p.y - q.y;        else                return p.x - q.x;}friend Vector operator + (Point p,Point q){        return Vector(p.x + q.x , p.y + q.y);}friend Vector operator - (Point p,Point q){        return Vector(p.x - q.x ,  p.y - q.y);}friend Vector operator * (Point p,double t){        return Vector(p.x * t , p.y * t);}friend Vector operator / (Point p,double t){        return Vector(p.x / t , p.y / t);}friend bool operator == (Point p,Point q){        return dcmp(p.x - q.x) == 0 && dcmp(p.y - q.y) == 0;}};double Dot(Vector p, Vector q){  //向量点积return p.x * q.x + p.y * q.y;}double Length(Vector p){        //向量长度return sqrt(p.x*p.x + p.y * p.y);}double Angle(Vector p ,Vector q){return acos( Dot(p, q) /( Length(p) * Length(q) ) );}double Cross(Vector p,Vector q){return p.x * q.y - p.y * q.x;}double Area(Point a,Point b,Point c){return Cross(a - b , c - b);}Vector Rotate(Vector p,double angle){ return Vector(p.x * cos(angle) - p.y * sin(angle), p.x * sin(angle) + p.y * cos(angle));}Vector Normal(Vector p){  //求法向量double L = Length(p);return Vector( - p.y / L , p.x / L);}Point GetLineCross(Vector v,Point p,Vector w,Point q){Vector u = p - q;double t = Cross(w,u) / Cross(v,w);return p + v * t;}double Distance(Point p,Point a,Point b){  //点到射线的距离    Vector v1 = b - a;    Vector v2 = p - a;    return fabs(Cross(v1,v2)) / Length(v1);}double Distance2(Point p,Point a,Point b){    if(a == b)        return Length(p - a);    Vector v1 = b - a , v2 = p - a, v3 = p - b;    if(dcmp(Dot(v1,v2)) < 0)        return Length(v2);    else if(dcmp(Dot(v1,v3)) > 0)        return Length(v3);    else        return fabs(Cross(v1,v2))/ Length(v1);}Point GetLinePoint(Point p,Point a,Point b){    Vector v = b - a;    return a + v *  (Dot(v, p -a ) / Dot(v,v));}bool If_Cross(Point a1,Point a2,Point b1,Point b2){    double c1 = Cross(a2 - a1 , b1 - a1) , c2 = Cross(a2 - a1 , b2 - a1),                  c3 = Cross(b2 - b1, a1 - b1),  c4  = Cross(b2 - b1, a2 - b1);    return dcmp(c1) * dcmp(c2) < 0 && dcmp(c3) * dcmp(c4) < 0;}bool If_InLine(Point p,Point a1,Point a2){    return dcmp(Cross(a1 - p , a2 - p)) == 0 && dcmp(Dot(a1 - p , a2 - p)) < 0;}Point GetPoint(Point a,Point b,Point c){    Vector v1 = c - b;    double rad = Angle(a - b,v1);    v1 = Rotate(v1, rad / 3);    Vector v2 = b - c;    double _rad = Angle(a - c, v2); //负数代表顺时钟转动    v2 = Rotate(v2, - _rad / 3);    return GetLineCross(v1,b,v2,c);}int main(){    int T;    scanf("%d",&T);    while(T--){        Point a , b , c;        scanf("%lf%lf",&a.x,&a.y);        scanf("%lf%lf",&b.x,&b.y);        scanf("%lf%lf",&c.x,&c.y);        Point d = GetPoint(a,b,c);        Point e = GetPoint(b,c,a);        Point f = GetPoint(c,a,b);        printf("%.6f %.6f %.6f %.6f %.6f %.6f\n",d.x,d.y,e.x,e.y,f.x,f.y);    }    return 0;}