Dog Distance UVA

代码

struct Point{    Point() = default;    double x,y;    Point(double x,double y):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)&&!dcmp(a.y-b.y);}//.....................................................//点乘double Dot(Vector A,Vector B){    return A.x*B.x+A.y*B.y;}//求模double Length(Vector A){    return sqrt(A.x*A.x+A.y*A.y);}//求斜率double Angle(Vector A,Vector B){    return acos(Dot(A,B)/Length(A)/Length(B));}//叉乘double Cross(Vector A,Vector B){    return A.x*B.y - A.y*B.x;}//求三角形面积double Area2(Point A,Point B,Point C){    return fabs(Cross(B-A,C-A))/2;}//旋转一定度数，弧度制Vector Rotate(Vector A,double rad){    return Vector (A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));}//单位法线Vector Normal(Vector A){    double L = Length(A);    return Vector(-A.y/L,A.x/L);}//调用前确保直线有唯一交点，当且仅当Cross(v,w)非0//求直线的交点Point Get_Line_Intersection(Point P,Vector v,Point Q,Vector w){    Vector u = P - Q;    double t = Cross(w,u)/Cross(v,w);    return P+v*t;}//点到直线的距离double Distance_To_Line(Point P,Point A,Point B){    Vector v1 = B-A,v2 = P-A;    return fabs(Cross(v1,v2)/Length(v1));}//点到线段的距离double Distance_To_Segment(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);}//求投影点Point Get_Line_Projection(Point P,Point A,Point B){    Vector v = B- A;    return A + v*(Dot(v,P-A)/Dot(v,v));}//线段相交判定 相交不在线段的端点bool Segment_Proper_Intersection(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,a2-b1),c4 = Cross(b2-b1,a1-b1);    return dcmp(c1)*dcmp(c2)<0&&dcmp(c3)*dcmp(c4)<0;}//判断点是否在线段上(不包括端点）bool Onsegment(Point p,Point a1,Point a2){    return dcmp(Cross(a1-p,a2-p))==0&&dcmp(Dot(a1-p,a2-p))<0;}bool Intersect_Onsegment(Point a,Point b,Point c,Point d){    return Onsegment(a,c,d)||Onsegment(b,c,d)||Onsegment(c,a,b)||Onsegment(d,a,b);}Point a[100];Point b[100];double Min = inf,Max = -inf;void Update(Point A,Point B,Point C){    Min = min(Min,Distance_To_Segment(A,B,C));    Max = max(Max,Length(B-A));    Max = max(Max,Length(C-A));}int main(void){    int T;    cin>>T;    int kase = 0;    int A,B;    while(T--)    {       scanf("%d %d",&A,&B);       for(int i = 0;i < A; ++i)            scanf("%lf %lf",&a[i].x,&a[i].y);       for(int i = 0;i < B; ++i)            scanf("%lf %lf",&b[i].x,&b[i].y);       double LenA = 0,LenB = 0;       for(int i = 0;i < A-1; ++i)        LenA += Length(a[i+1]-a[i]);       for(int i = 0;i < B-1; ++i)        LenB += Length(b[i+1]-b[i]);       int Sa = 0,Sb = 0;       Point Pa,Pb;       Pa = a[0];       Pb = b[0];       Min = inf,Max = -inf;       while(Sa<A-1&&Sb<B-1)       {          double da = Length(a[Sa+1]-Pa);          double db = Length(b[Sb+1]-Pb);          double T = min(da/LenA,db/LenB);          Vector va = (a[Sa+1]-Pa)/da*T*LenA;          Vector vb = (b[Sb+1]-Pb)/db*T*LenB;          Update(Pa,Pb,Pb+vb-va);          Pa = Pa + va;          Pb = Pb + vb;          if(a[Sa+1]==Pa) Sa++;          if(b[Sb+1]==Pb) Sb++;       }        printf("Case %d: %.f\n",++kase,round(Max-Min));    }    return 0;}