QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#522014#7065. TriangleasitshouldbeAC ✓2068ms4132kbC++1428.5kb2024-08-16 17:25:192024-08-16 17:25:19

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  • [2024-08-16 17:25:19]
  • 评测
  • 测评结果:AC
  • 用时:2068ms
  • 内存:4132kb
  • [2024-08-16 17:25:19]
  • 提交

answer

#include <bits/stdc++.h>
#define pi acos(-1.0)
//#define double long double
using namespace std;
const double eps = 1e-8,inf=1e12;
const int N=1e3+10;
int sgn(double x)
{
    if(fabs(x) < eps) return 0;
    if(x < 0) return -1;
    else return 1;
}
int dsgn(double x,double y)
{
    if(fabs(x-y)<eps) return 0;
    if(x<y) return -1;
    else return 1;
}

inline double sqr(double x){return x*x;}

struct Point
{
    double x,y;
    Point(){}
    Point(double _x,double _y){x = _x;y = _y;}
    void input(){cin>>x>>y;}
    bool operator == (Point b)const{
        return sgn(x-b.x) == 0 && sgn(y-b.y) == 0;
    }
    bool operator < (Point b)const{
        return sgn(x-b.x)== 0?sgn(y-b.y)<0:x<b.x; 
    }
    Point operator -(const Point &b)const{return Point(x-b.x,y-b.y);}
    Point operator +(const Point &b)const{return Point(x+b.x,y+b.y);}
    //叉积
    double operator ^(const Point &b)const{return x*b.y - y*b.x;}
    //点积
    double operator *(const Point &b)const{return x*b.x + y*b.y;}   
    //数乘
    Point operator *(const double &k)const{
        return Point(x*k,y*k);
    }
    Point operator /(const double &k)const{
        return Point(x/k,y/k);
    }
    //返回长度
    double len(){return hypot(x,y);}
    //返回长度的平方
    double len2(){return x*x + y*y;}
    //返回两点的距离
    double distance(Point p){return hypot(x-p.x,y-p.y);}
    int distance2(Point p){return (x-p.x)*(x-p.x)+(y-p.y)*(y-p.y);}
    //`计算pa  和  pb 的夹角 就是求这个点看a,b 所成的夹角`
    //`测试 LightOJ1203`
    double rad(Point a,Point b){
        Point p = *this;
        return fabs(atan2( fabs((a-p)^(b-p)),(a-p)*(b-p) ));
    }
    //`绕着p点逆时针旋转angle`
    Point rotate(Point p,double angle)
    {
        Point v = (*this) - p;
        double c = cos(angle), s = sin(angle);
        return Point(p.x + v.x*c - v.y*s,p.y + v.x*s + v.y*c);
    }
    //`化为长度为r的向量`
    Point trunc(double r){
        double l = len();
        if(!sgn(l))return *this;
        r /= l;
        return Point(x*r,y*r);
    }
    //`逆时针旋转90度`
    Point rotleft(){return Point(-y,x);}
    //`顺时针旋转90度`;
    Point rotright(){return Point(y,-x);}
};
//`AB X AC`
double cross(Point A,Point B,Point C){return (B-A)^(C-A);}
//`AB*AC`
double dot(Point A,Point B,Point C){return (B-A)*(C-A);}

struct Line{
    Point s,e;
    Line(){}
    Line(Point _s,Point _e){s = _s;e = _e;}
    bool operator ==(Line v){
        return (s == v.s)&&(e == v.e);
    }
    //`根据一个点和倾斜角angle确定直线,0<=angle<pi`
    Line(Point p,double angle){
        s = p;
        if(sgn(angle-pi/2) == 0){e = (s + Point(0,1));}
        else{e = (s + Point(1,tan(angle)));}
    }
    //ax+by+c=0
    Line(double a,double b,double c){
        if(sgn(a) == 0){
            s = Point(0,-c/b);
            e = Point(1,-c/b);
        }
        else if(sgn(b) == 0){
            s = Point(-c/a,0);
            e = Point(-c/a,1);
        }
        else{
            s = Point(0,-c/b);
            e = Point(1,(-c-a)/b);
        }
    }
    void input(){s.input();e.input();}
    void adjust(){if(e < s)swap(s,e);}
    //求线段长度
    double length(){return s.distance(e);}
    //`返回直线倾斜角 0<=angle<pi`
    double angle(){
        double k = atan2(e.y-s.y,e.x-s.x);
        //if(sgn(k) < 0)k += pi;
        //if(sgn(k-pi) == 0)k -= pi;
        return k;
    }
    bool operator <(Line& v){
        return sgn(angle()-v.angle())==0?((e-s)^(v.e-s))<0:angle()<v.angle();
    }
    //`点和直线关系`
    int relation(Point p){
        int c = sgn((p-s)^(e-s));
        if(c < 0)return 1;        //`1  在左侧`
        else if(c > 0)return 2;   //`2  在右侧`
        else return 3;            //`3  在直线上`
    }
    //`点在线段上的判断`
    bool pointonseg(Point p){
        return sgn((p-s)^(e-s)) == 0 && sgn((p-s)*(p-e)) <= 0;
    }
    //`两向量平行(对应直线平行或重合)`
    bool parallel(Line v){
        return sgn((e-s)^(v.e-v.s)) == 0;
    }
    //`两向量正交`
    bool orthogonal(Line v){
        return sgn((e-s)*(v.e-v.s)) == 0;
    }
    //`两直线关系`
    int linecrossline(Line v){
        if((*this).parallel(v))             //`0 平行`
            return v.relation(s)==3;        //`1 重合`
        if((*this).orthogonal(v)) return 3; //`3 正交`
        else return 2;                      //`2 相交`
    }
    //`两线段相交判断`
    int segcrossseg(Line v){
        int d1 = sgn((e-s)^(v.s-s));
        int d2 = sgn((e-s)^(v.e-s));
        int d3 = sgn((v.e-v.s)^(s-v.s));
        int d4 = sgn((v.e-v.s)^(e-v.s));
        if( (d1^d2)==-2 && (d3^d4)==-2 )return 2;    //`2 规范相交`
        return (d1==0 && sgn((v.s-s)*(v.s-e))<=0) || //`1 非规范相交`
            (d2==0 && sgn((v.e-s)*(v.e-e))<=0) ||    //`0 不相交`
            (d3==0 && sgn((s-v.s)*(s-v.e))<=0) ||
            (d4==0 && sgn((e-v.s)*(e-v.e))<=0);
    }
    //`直线和线段相交判断`
    int linecrossseg(Line v){
        int d1 = sgn((e-s)^(v.s-s));
        int d2 = sgn((e-s)^(v.e-s));
        if((d1^d2)==-2) return 2;    //`2 规范相交`
        return (d1==0||d2==0);       //`1 非规范相交 0 不相交`
    }
    //`求两直线的交点  要保证两直线不平行或重合`
    Point crosspoint(Line l)
    {
        Point u=e-s,v=l.e-l.s;
        double t=(s-l.s)^v/(v^u);
        return s+u*t;
    }
    //`返回点p在直线上的投影`
    Point lineprog(Point p){
        Point u=e-s,v=p-s;
        return s + u*(u*v/u.len2());
    }
    //点到直线的距离
    double dispointtoline(Point p){
        return fabs((p-s)^(e-s))/length();
    }
    //点到线段的距离
    double dispointtoseg(Point p){
        if(sgn((p-s)*(e-s))<0 || sgn((p-e)*(s-e))<0)
            return min(p.distance(s),p.distance(e));
        return dispointtoline(p);
    }
    //`返回线段到线段的距离 前提是两线段不相交,相交距离就是0了`
    double dissegtoseg(Line v){
        return min(min(dispointtoseg(v.s),dispointtoseg(v.e)),min(v.dispointtoseg(s),v.dispointtoseg(e)));
    }
    //`返回点p关于直线的对称点`
    Point symmetrypoint(Point p){
        Point pro = lineprog(p);
        return pro*2-p;
    }
};

struct circle{
    Point p;//圆心
    double r;//半径
    circle(){}
    circle(Point _p,double _r){p = _p;r = _r;}
    circle(double x,double y,double _r){p = Point(x,y);r = _r;}
    //`三角形的外接圆`
    //`需要Point的+ /  rotate()  以及Line的crosspoint()`
    //`利用两条边的中垂线得到圆心`
    //`测试:UVA12304`
    circle(Point a,Point b,Point c){
        Line u = Line((a+b)/2,((a+b)/2)+((b-a).rotleft()));
        Line v = Line((b+c)/2,((b+c)/2)+((c-b).rotleft()));
        p = u.crosspoint(v);
        r = p.distance(a);
    }
    //`三角形的内切圆`
    //`参数bool t没有作用,只是为了和上面外接圆函数区别`
    //`测试:UVA12304`
    circle(Point a,Point b,Point c,bool t){
        Line u,v;
        double m = atan2(b.y-a.y,b.x-a.x), n = atan2(c.y-a.y,c.x-a.x);
        u.s = a;
        u.e = u.s + Point(cos((n+m)/2),sin((n+m)/2));
        v.s = b;
        m = atan2(a.y-b.y,a.x-b.x) , n = atan2(c.y-b.y,c.x-b.x);
        v.e = v.s + Point(cos((n+m)/2),sin((n+m)/2));
        p = u.crosspoint(v);
        r = Line(a,b).dispointtoseg(p);
    }
    //输入
    void input(){p.input();cin>>r;}
    bool operator == (circle v){
        return (p==v.p) && sgn(r-v.r)==0;
    }
    bool operator < (circle v)const{
        return ((p<v.p)||((p==v.p)&&sgn(r-v.r)<0));
    }
    //面积
    double area(){return pi*r*r;}
    //周长
    double circumference(){return 2*pi*r;}
    //`点和圆的关系`
    int relation(Point b){
        double dst = b.distance(p);
        if(sgn(dst-r) < 0)return 2;     //`2 圆内`
        else if(sgn(dst-r)==0)return 1; //`1 圆上`
        return 0;                       //`0 圆外`
    }
    //`线段和圆的关系 比较的是圆心到线段的距离和半径的关系`
    int relationseg(Line v){
        double dst = v.dispointtoseg(p);
        if(sgn(dst-r) < 0)return 2;       //`2 相交`
        else if(sgn(dst-r) == 0)return 1; //`1 相切`
        return 0;                         //`0 相离`
    }
    //`直线和圆的关系 比较的是圆心到直线的距离和半径的关系`
    int relationline(Line v){
        double dst = v.dispointtoline(p);
        if(sgn(dst-r) < 0)return 2;       //`2 相交`
        else if(sgn(dst-r) == 0)return 1; //`1 相切`
        return 0;                         //`0 相离`
    }
    //`两圆的关系 需要Point的distance`
    //`测试:UVA12304`
    int relationcircle(circle v){
        double d = p.distance(v.p);
        if(sgn(d-r-v.r) > 0)return 5;             //`5 相离`
        if(sgn(d-r-v.r) == 0)return 4;            //`4 外切`
        double l = fabs(r-v.r);
        if(sgn(d-r-v.r)<0 && sgn(d-l)>0)return 3; //`3 相交`
        if(sgn(d-l)==0)return 2;                  //`2 内切`
        if(sgn(d-l)<0)return 1;                   //`1 内含`
    }
    //`求两个圆的交点 需要relationcircle`
    //`测试:UVA12304`
    int pointcrosscircle(circle v,Point &p1,Point &p2){
        int rel = relationcircle(v);
        if(rel == 1 || rel == 5)return 0;         //`0 无交点`
        double d = p.distance(v.p);
        double l = (d*d+r*r-v.r*v.r)/(2*d);
        double h = sqrt(r*r-l*l);
        Point tmp = p + (v.p-p).trunc(l);
        p1 = tmp + ((v.p-p).rotleft().trunc(h));
        p2 = tmp + ((v.p-p).rotright().trunc(h));
        if(rel == 2 || rel == 4) return 1;        //`1 一个交点`
        return 2;                                 //`2 两个交点`
    }
    //`求直线和圆的交点,返回交点个数`
    int pointcrossline(Line v,Point &p1,Point &p2){
        if(!(*this).relationline(v))return 0;
        Point a = v.lineprog(p);
        double d = v.dispointtoline(p);
        d = sqrt(r*r-d*d);
        if(sgn(d) == 0){
            p1 = a;
            p2 = a;
            return 1;
        }
        p1 = a + (v.e-v.s).trunc(d);
        p2 = a - (v.e-v.s).trunc(d);
        return 2;
    }
    //`得到过a,b两点,半径为r1的两个圆`
    int gercircle(Point a,Point b,double r1,circle &c1,circle &c2){
        circle x(a,r1),y(b,r1);
        int t = x.pointcrosscircle(y,c1.p,c2.p);
        if(!t)return 0;
        c1.r = c2.r = r;
        return t; //`返回圆的个数`
    }
    //`得到与直线u相切,过点q,半径为r1的圆`
    //`测试:UVA12304`
    int getcircle(Line u,Point q,double r1,circle &c1,circle &c2){
        double dis = u.dispointtoline(q);
        if(sgn(dis-r1*2)>0)return 0;
        if(sgn(dis) == 0){
            c1.p = q + ((u.e-u.s).rotleft().trunc(r1));
            c2.p = q + ((u.e-u.s).rotright().trunc(r1));
            c1.r = c2.r = r1;
            return 2;
        }
        Line u1 = Line((u.s + (u.e-u.s).rotleft().trunc(r1)),(u.e + (u.e-u.s).rotleft().trunc(r1)));
        Line u2 = Line((u.s + (u.e-u.s).rotright().trunc(r1)),(u.e + (u.e-u.s).rotright().trunc(r1)));
        circle cc = circle(q,r1);
        Point p1,p2;
        if(!cc.pointcrossline(u1,p1,p2))cc.pointcrossline(u2,p1,p2);
        c1 = circle(p1,r1);
        if(p1 == p2){
            c2 = c1;
            return 1;
        }
        c2 = circle(p2,r1);
        return 2;
    }
    //`同时与直线u,v相切,半径为r1的圆`
    //`测试:UVA12304`
    int getcircle(Line u,Line v,double r1,circle &c1,circle &c2,circle &c3,circle &c4){
        if(u.parallel(v))return 0;//两直线平行
        Line u1 = Line(u.s + (u.e-u.s).rotleft().trunc(r1),u.e + (u.e-u.s).rotleft().trunc(r1));
        Line u2 = Line(u.s + (u.e-u.s).rotright().trunc(r1),u.e + (u.e-u.s).rotright().trunc(r1));
        Line v1 = Line(v.s + (v.e-v.s).rotleft().trunc(r1),v.e + (v.e-v.s).rotleft().trunc(r1));
        Line v2 = Line(v.s + (v.e-v.s).rotright().trunc(r1),v.e + (v.e-v.s).rotright().trunc(r1));
        c1.r = c2.r = c3.r = c4.r = r1;
        c1.p = u1.crosspoint(v1);
        c2.p = u1.crosspoint(v2);
        c3.p = u2.crosspoint(v1);
        c4.p = u2.crosspoint(v2);
        return 4;
    }
    //`同时与不相交圆cx,cy相切,半径为r1的圆`
    //`测试:UVA12304`
    int getcircle(circle cx,circle cy,double r1,circle &c1,circle &c2){
        circle x(cx.p,r1+cx.r),y(cy.p,r1+cy.r);
        int t = x.pointcrosscircle(y,c1.p,c2.p);
        if(!t)return 0;
        c1.r = c2.r = r1;
        return t; //`返回圆的个数`
    }
    //`过一点作圆的切线(先判断点和圆的关系)`
    //`测试:UVA12304`
    int tangentline(Point q,Line &u,Line &v){
        int x = relation(q);
        if(x == 2)return 0;
        if(x == 1){
            u = Line(q,q + (q-p).rotleft());
            v = u;
            return 1;
        }
        double d = p.distance(q);
        double l = r*r/d;
        double h = sqrt(r*r-l*l);
        u = Line(q,p + ((q-p).trunc(l) + (q-p).rotleft().trunc(h)));
        v = Line(q,p + ((q-p).trunc(l) + (q-p).rotright().trunc(h)));
        return 2; //`返回切线的个数`
    }
    int tangentpoint(Point q,Point &u,Point &v){
        int x = relation(q);
        if(x == 2)return 0;
        if(x == 1){
            u = q;v = u;
            return 1;
        }
        double d = p.distance(q);
        double l = r*r/d;
        double h = sqrt(r*r-l*l);
        u = p + ((q-p).trunc(l) + (q-p).rotleft().trunc(h));
        v = p + ((q-p).trunc(l) + (q-p).rotright().trunc(h));
        return 2; //`返回切点的个数`
    }    
    //`求两圆相交的面积`
    double areacircle(circle v){
        int rel = relationcircle(v);
        if(rel >= 4)return 0.0;
        if(rel <= 2)return min(area(),v.area());
        double d = p.distance(v.p);
        double hf = (r+v.r+d)/2.0;
        double ss = 2*sqrt(hf*(hf-r)*(hf-v.r)*(hf-d));
        double a1 = acos((r*r+d*d-v.r*v.r)/(2.0*r*d));
        a1 = a1*r*r;
        double a2 = acos((v.r*v.r+d*d-r*r)/(2.0*v.r*d));
        a2 = a2*v.r*v.r;
        return a1+a2-ss;
    }
    //`求圆和三角形pab的相交面积`
    //`测试:POJ3675 HDU3982 HDU2892`
    double areatriangle(Point a,Point b){
        if(sgn((p-a)^(p-b)) == 0)return 0.0;
        Point q[5];
        int len = 0;
        q[len++] = a;
        Line l(a,b);
        Point p1,p2;
        if(pointcrossline(l,q[1],q[2])==2){
            if(sgn((a-q[1])*(b-q[1]))<0)q[len++] = q[1];
            if(sgn((a-q[2])*(b-q[2]))<0)q[len++] = q[2];
        }
        q[len++] = b;
        if(len == 4 && sgn((q[0]-q[1])*(q[2]-q[1]))>0)swap(q[1],q[2]);
        double res = 0;
        for(int i = 0;i < len-1;i++){
            if(relation(q[i])==0||relation(q[i+1])==0){
                double arg = p.rad(q[i],q[i+1]);
                res += r*r*arg/2.0;
            }
            else res += fabs((q[i]-p)^(q[i+1]-p))/2.0;
        }
        return res;
    }
    //`两圆公切线`
    Point getpoint(double rad){return Point(p.x+r*cos(rad),p.y+r*sin(rad));}
    int conmontangent(circle v,vector<Point> &p1,vector<Point> &p2)
    {
        bool flag=0;
        if(r<v.r) swap(*this,v),flag=1;
        double d=p.distance(v.p),rd=r-v.r,rs=r+v.r;
        if(sgn(d-rd)<0) return 0;
        if(sgn(d)==0) return -1;
        double rad=Line(p,v.p).angle();
        if(sgn(d-rd)==0)
        {
            p1.push_back(getpoint(rad)),p2.push_back(getpoint(rad));
            return 1; //`一条外公切线`
        }
        double rad1=acos(rd/d);
        p1.push_back(getpoint(rad+rad1)),p2.push_back(v.getpoint(rad+rad1));
        p1.push_back(getpoint(rad-rad1)),p2.push_back(v.getpoint(rad-rad1));
        if(sgn(d-rs)==0)
        {
            p1.push_back(getpoint(rad)),p2.push_back(getpoint(rad));
            if(flag) swap(p1,p2);
            return 3; //`两条外公切线 一条内公切线`
        }
        else if(sgn(d-rs)>0)
        {
            double rad2=acos(rs/d);
            p1.push_back(getpoint(rad+rad2)),p2.push_back(v.getpoint(rad+rad2-pi));
            p1.push_back(getpoint(rad-rad2)),p2.push_back(v.getpoint(rad-rad2+pi));
            if(flag) swap(p1,p2);
            return 4; //`两条外公切线 两条内公切线`
        }
        else
        {
            if(flag) swap(p1,p2);
            return 2; //`两条外公切线`
        }
    }
};

struct polygon{
    int n;
    Point p[N];
    Line l[N];
    void input(int _n){
        n = _n;
        for(int i = 0;i < n;i++)
            p[i].input();
    }
    void add(Point q){p[n++] = q;}
    void getline(){
        for(int i = 0;i < n;i++){
            l[i] = Line(p[i],p[(i+1)%n]);
        }
    }

    struct cmp{
        Point p;
        cmp(const Point &p0){p = p0;}
        bool operator()(const Point &aa,const Point &bb){
            Point a = aa, b = bb;
            int d = sgn((a-p)^(b-p));
            if(d == 0){
                return sgn(a.distance(p)-b.distance(p)) < 0;
            }
            return d > 0;
        }
    };
    //`进行极角排序 mi为极点`
    //`需要重载号好Point的 < 操作符(min函数要用) `
    void norm(Point mi){
        //Point mi = p[0];
        //for(int i = 1;i < n;i++)mi = min(mi,p[i]);
        sort(p,p+n,cmp(mi));
    }

    //`得到凸包`
    //`得到的凸包里面的点编号是0-n-1的`
    //`两种凸包的方法`
    //`注意如果有影响,要特判下所有点共点,或者共线的特殊情况`
    //`测试 LightOJ1203  LightOJ1239`
    void andrew(polygon &convex){
        sort(p,p+n);
        int &top = convex.n;
        top = 0;
        for(int i = 0;i < n;i++){
            while(top>=2&&sgn(cross(convex.p[top-2],convex.p[top-1],p[i]))<=0) top--;
            convex.p[top++] = p[i];
        }
        int temp = top;
        for(int i = n-2;i >= 0;i--){
            while(top>temp&&sgn(cross(convex.p[top-2],convex.p[top-1],p[i]))<=0) top--;
            convex.p[top++] = p[i];
        }
        top--;
    }
    //`判断是不是凸的`
    bool isconvex(){
        bool s[5];
        memset(s,false,sizeof(s));
        for(int i = 0;i < n;i++){
            int j = (i+1)%n,k = (j+1)%n;
            s[sgn((p[j]-p[i])^(p[k]-p[i]))+1] = true;
            if(s[0] && s[2])return false;
        }
        return true;
    }
    //`判断点和任意多边形的关系`
    int relationpoint(Point q){
        for(int i = 0;i < n;i++){
            if(p[i] == q)return 3;             //` 3 点上`
        }
        getline();
        for(int i = 0;i < n;i++){
            if(l[i].pointonseg(q))return 2;    //` 2 边上`
        }
        int cnt = 0;
        for(int i = 0;i < n;i++){
            int j = (i+1)%n;
            int k = sgn((q-p[j])^(p[i]-p[j]));
            int u = sgn(p[i].y-q.y);
            int v = sgn(p[j].y-q.y);
            if(k > 0 && u < 0 && v >= 0)cnt++;
            if(k < 0 && v < 0 && u >= 0)cnt--;
        }                                      //` 1 内部`
        return cnt != 0;                       //` 0 外部`
    }
    //`直线u切割凸多边形左侧 注意直线方向`
    //`测试:HDU3982`
    void convexcut(Line u,polygon &po){
        int &top = po.n;//注意引用
        top = 0;
        for(int i = 0;i < n;i++){
            int d1 = sgn((u.e-u.s)^(p[i]-u.s));
            int d2 = sgn((u.e-u.s)^(p[(i+1)%n]-u.s));
            if(d1 >= 0)po.p[top++] = p[i];
            if(d1*d2 < 0)po.p[top++] = u.crosspoint(Line(p[i],p[(i+1)%n]));
        }
    }
    //`得到周长`
    //`测试 LightOJ1239`
    double getcircumference(){
        double sum = 0;
        for(int i = 0;i < n;i++) sum += p[i].distance(p[(i+1)%n]);
        return sum;
    }
    //`得到面积`
    double getarea(){
        double sum = 0;
        for(int i = 0;i < n;i++) sum += (p[i]^p[(i+1)%n]);
        return fabs(sum)/2;
    }
    //`得到方向`
    bool getdir(){
        double sum = 0;
        for(int i = 0;i < n;i++)
            sum += (p[i]^p[(i+1)%n]);
        if(sgn(sum) > 0)return 1;     //` 1 逆时针`
        else return 0;                //` 0 顺时针`
    }
    //`得到重心`
    Point getbarycentre(){
        Point ret(0,0);
        double area = 0;
        for(int i = 1;i < n-1;i++){
            double tmp = (p[i]-p[0])^(p[i+1]-p[0]);
            if(sgn(tmp) == 0)continue;
            area += tmp;
            ret.x += (p[0].x+p[i].x+p[i+1].x)/3*tmp;
            ret.y += (p[0].y+p[i].y+p[i+1].y)/3*tmp;
        }
        if(sgn(area)) ret = ret/area;
        return ret;
    }
    //`多边形和圆交的面积`
    //`测试:POJ3675 HDU3982 HDU2892`
    double areacircle(circle c){
        double ans = 0;
        for(int i = 0;i < n;i++){
            int j = (i+1)%n;
            if(sgn( (p[j]-c.p)^(p[i]-c.p) ) >= 0)
                ans += c.areatriangle(p[i],p[j]);
            else ans -= c.areatriangle(p[i],p[j]);
        }
        return fabs(ans);
    }
    //`多边形和圆关系`
    int relationcircle(circle c){
        getline();
        int x = 2;                              //` 2 圆完全在多边形内`
        if(relationpoint(c.p) != 1)return 0;    //` 0 圆心不在内部`
        for(int i = 0;i < n;i++){
            if(c.relationseg(l[i])==2)return 0; //` 0 其它`
            if(c.relationseg(l[i])==1)x = 1;    //` 1 圆在多边形里面,碰到了多边形边界`
        }
        return x;
    }
    //`旋转卡壳求凸包直径(最远点对)`
    double rorating_calipers1()
    {
        double res=0;
        for(int i=0,j=1;i<n;i++)
        {
            while(dsgn(cross(p[i],p[i+1],p[j]),cross(p[i],p[i+1],p[j+1]))<0) j=(j+1)%n;
            res=max(res,max(p[i].distance(p[j]),p[i+1].distance(p[j])));
        }
        return res;
    }
    //`旋转卡壳求最小矩形覆盖`
    double rorating_calipers2(polygon &pt)
    {
        double res=1e20;
        for(int i=0,a=1,b=1,c;i<n;i++)
        {
            while(dsgn(cross(p[i],p[i+1],p[a]),cross(p[i],p[i+1],p[a+1]))<0) a=(a+1)%n;
            while(dsgn(dot(p[i],p[i+1],p[b]),dot(p[i],p[i+1],p[b+1]))<0) b=(b+1)%n;
            if(!i) c=a;
            while(dsgn(dot(p[i+1],p[i],p[c]),dot(p[i+1],p[i],p[c+1]))<0) c=(c+1)%n;
            double d=p[i].distance(p[i+1]);
            double H=cross(p[i],p[i+1],p[a])/d;
            double R=dot(p[i],p[i+1],p[b])/d;
            double L=dot(p[i+1],p[i],p[c])/d;
            if(dsgn(res,(L+R-d)*H)>0)
            {
                res=(L+R-d)*H;
                pt.p[0]=p[i+1]+(p[i]-p[i+1])*(L/d);
                pt.p[1]=p[i]+(p[i+1]-p[i])*(R/d);
                pt.p[2]=pt.p[1]+(p[i+1]-p[i]).rotleft()*(H/d);
                pt.p[3]=pt.p[0]+(p[i+1]-p[i]).rotleft()*(H/d);
            }
        }
        return res;
    }
    //`分治法求最近点对`
    Point a[N];
    double divide(int l,int r)
    {
        if(l==r) return 2e9;
        if(l+1==r) return p[l].distance(p[r]);
        int mid=l+r>>1;
        double d=min(divide(l,mid),divide(mid+1,r));
        int k=0;
        for(int i=l;i<=r;i++)
            if(fabs(p[mid].x-p[i].x)<d) a[k++]=p[i];
        //sort(a,a+k,[&](Point a,Point b)->bool {return a.y<b.y;});
        for(int i=0;i<k;i++)
            for(int j=i+1;j<k&&a[j].y-a[i].y<d;j++)
                d=min(d,a[j].distance(a[i]));
        return d;
    }
    //`旋转卡壳求最大三角形面积`
    double rotating_calipers3()
    {
        double res=0;
        for(int i=0;i<n;i++)
        {
            int k=i+1;
            for(int j=i+1;j<n;j++)
            {
                while(dsgn(cross(p[i],p[j],p[k]),cross(p[i],p[j],p[k+1]))<0) k=(k+1)%n;
                res=max(res,cross(p[i],p[j],p[k]));
            }
        }
        return res/2;
    }
};
//`半平面交求凸多边形面积交`
double half_plane1(Line l[],int n)
{
    double res=0;
    sort(l,l+n);
    Line q[N];Point p[N];
    int h=0,t=0,k=0;q[t++]=l[0];
    for(int i=1;i<n;i++)
    {
        if(sgn(l[i].angle()-l[i-1].angle())==0) continue;
        while(h<t-1&&l[i].relation(q[t-1].crosspoint(q[t-2]))==2) t--;
        while(h<t-1&&l[i].relation(q[h].crosspoint(q[h+1]))==2) h++;
        q[t++]=l[i];
    }
    while(h<t-1&&l[h].relation(q[t-1].crosspoint(q[t-2]))==2) t--;
    q[t++]=q[h];
    for(int i=h;i<t-1;i++) p[k++]=q[i].crosspoint(q[i+1]);
    for(int i=1;i<k-1;i++) res+=(p[i]-p[0])^(p[i+1]-p[0]);
    return res/2;
}
//`水平可见直线 从上向下看输出能看见哪些直线`
void half_plane2(Line l[],int n)
{
    sort(l,l+n);
    Line q[N];
    int h=0,t=0,k=0;q[t++]=l[0];
    for(int i=1;i<n;i++)
    {
        if(sgn(l[i].angle()-l[i-1].angle())==0) continue;
        while(h<t-1&&l[i].relation(q[t-1].crosspoint(q[t-2]))==2) t--;
        // while(h<t-1&&l[i].relation(q[h].crosspoint(q[h+1]))==2) h++;
        q[t++]=l[i];
    }
    int ans[N];
    for(int i=h;i<t;i++)
        //for(auto j:q[i].id) ans[k++]=j;
    sort(ans,ans+k);
    cout<<k<<endl;
    for(int i=0;i<k;i++) cout<<ans[i]<<" ";
}
//`多边形内核`
bool half_plane3(Line l[],int n)
{
    sort(l,l+n);
    Line q[N];
    int h=0,t=0;q[t++]=l[0];
    for(int i=1;i<n;i++)
    {
        if(sgn(l[i].angle()-l[i-1].angle())==0) continue;
        while(h<t-1&&l[i].relation(q[t-1].crosspoint(q[t-2]))==2) t--;
        while(h<t-1&&l[i].relation(q[h].crosspoint(q[h+1]))==2) h++;
        q[t++]=l[i];
    }
    while(h<t-1&&l[h].relation(q[t-1].crosspoint(q[t-2]))==2) t--;
    return t-h>=3;
}
//`最小圆覆盖`
circle increment(Point p[],int n)
{
    random_shuffle(p,p+n);
    circle ans;ans.p=p[0],ans.r=0;
    for(int i=1;i<n;i++)
        if(ans.r<ans.p.distance(p[i]))
        {
            ans.p=p[i],ans.r=0;
            for(int j=0;j<i;j++)
                if(ans.r<ans.p.distance(p[j]))
                {
                    ans.p=(p[i]+p[j])/2,ans.r=p[i].distance(p[j])/2;
                    for(int k=0;k<j;k++)
                        if(ans.r<ans.p.distance(p[k]))
                        {
                            Point p1=(p[i]+p[j])/2;
                            Point v1=(p[i]-p[j]).rotright();
                            Point p2=(p[i]+p[k])/2;
                            Point v2=(p[i]-p[k]).rotright();
                            ans.p=Line(p1,p1+v1).crosspoint(Line(p2,p2+v2));
                            ans.r=ans.p.distance(p[i]);
                        }
                }
        }
    return ans;
}
//`自适应辛普森积分`
inline double f(double x){ //积分函数
    return x;
}
double simpson(double l,double r){//辛普森公式
    double mid=(l+r)/2;
    return (r-l)*(f(l)+f(r)+4*f(mid))/6;
}
double asr(double l,double r,double ans){//自适应
    double mid=(l+r)/2;
    double a=simpson(l,mid),b=simpson(mid,r);
    if(sgn(a+b-ans)==0) return ans;
    return asr(l,mid,a)+asr(mid,r,b);
}

void solve()
{
    Point p1,p2,p3,p4,t;
    p1.input(),p2.input(),p3.input(),p4.input();
    polygon p;p.n=0;
    p.add(p1),p.add(p2),p.add(p3);
    int pr=p.relationpoint(p4);
    if(pr==1||pr==0)
    {
        cout<<-1<<endl;
        return;
    }
    if(pr==3)
    {
        if(p4==p1) t=(p2+p3)/2;
        else if(p4==p2) t=(p1+p3)/2;
        else t=(p1+p2)/2;
        cout<<fixed<<setprecision(6)<<t.x<<" "<<t.y<<endl;
    }
    else
    {
        if(p4==(p1+p2)/2) t=p3;
        else if(p4==(p2+p3)/2) t=p1;
        else if(p4==(p1+p3)/2) t=p2;
        else
        {
            double s=p.getarea();
            Line l[5];
            l[0]=Line(p1,p2);l[1]=Line(p2,p3);l[2]=Line(p1,p3);
            int idx;
            for(int i=0;i<3;i++)
                if(l[i].pointonseg(p4))
                {
                    idx=i;
                    break;
                }
            Point pf,a,b;
            if(p4.distance(l[idx].s)>p4.distance(l[idx].e)) pf=l[idx].s;
            else pf=l[idx].e;
            a=p4-pf;
            if(idx==0) b=p3-pf;
            else if(idx==1) b=p1-pf;
            else b=p2-pf;
            double L=0,R=1e10;
            while(sgn(R-L)>0)
            {
                double mid=(L+R)/2;
                if(sgn((fabs(a^b)*mid)-s)>=0) R=mid;
                else L=mid;  
            }
            t=b*L+pf;
        }
        cout<<fixed<<setprecision(6)<<t.x<<" "<<t.y<<endl;
    }
}

int main()
{
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    int t=1;cin>>t;
    while(t--) solve();
    return 0;
}

这程序好像有点Bug,我给组数据试试?

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 1ms
memory: 3872kb

input:

2
0 0 1 1 1 0 1 0
0 0 1 1 1 0 2 0

output:

0.500000 0.500000
-1

result:

ok 3 numbers

Test #2:

score: 0
Accepted
time: 1364ms
memory: 4120kb

input:

999966
9456 15557 18451 3957 6242 20372 9855 5351
30245 31547 9979 4703 25914 19144 26670 11383
13855 0 24614 0 15860 11017 12445 0
27870 17680 4219 3554 9129 29072 28316 17893
3249 27269 12754 4923 31746 16860 14894 21576
6846 0 1915 0 25023 28721 10508 0
10110 11862 23224 10373 17715 8212 29474 11...

output:

-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
21424.681316 13086.053760
-1
-1
18711.237945 10162.376221
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
28212.952107 245.817783
-1
-1
-1
-1
-1
-1
-1
-1
22604.575186 14546.128591
-1
-1
11557.346496 4668.209769
-1
-1
19488.201012 725.306...

result:

ok 1111378 numbers

Test #3:

score: 0
Accepted
time: 1356ms
memory: 4124kb

input:

999974
9228 16833 13143 23461 5117 7645 21359 13652
21313 3160 20333 1620 16288 7781 13315 10132
4372 0 27536 0 3207 8695 9983 0
21469 29998 19948 29904 30517 11141 14857 12881
11116 29172 16833 32095 18915 9448 22043 12275
32131 0 14304 0 16638 29018 2048 0
4695 4823 14130 2496 32676 4092 6363 2476...

output:

-1
-1
11482.990578 5737.223763
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
15409.841962 12451.427767
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
-1
10828.971323 25347.334689
-1
-1
-1
-1
-1
18768.672785 12151.367076
-1
-1
-1
-1
-1
10801.120586 5947.861748
-1
-1
-1
-1
-1
1...

result:

ok 1110866 numbers

Test #4:

score: 0
Accepted
time: 2068ms
memory: 4132kb

input:

1000000
54242 34392 23333 92971 5711 47765 54242 34392
24492 41078 36756 68794 2060 62118 14678 50283
12685 18891 59613 23256 26016 46755 59613 23256
85238 49611 95092 85360 45143 87657 95092 85360
72852 37174 39825 60628 32289 18423 72852 37174
95309 61613 1645 45877 78395 38196 95309 61613
92215 7...

output:

14522.000000 70368.000000
32900.888732 68052.222192
19350.500000 32823.000000
65190.500000 68634.000000
36057.000000 39525.500000
40020.000000 42036.500000
95183.499971 40970.499669
28582.000000 94834.500000
55598.000000 59174.000000
19727.000000 68648.000000
73385.000000 43885.500000
16466.000288 5...

result:

ok 2000000 numbers