hdu 5033 Building 几何+单调栈

          大概用一个单调栈存一下大楼的编号以及这个大楼可以控制的范围....然后乱搞一下...被虐了一下午精神有点恍惚，先贴代码，具体思路闲了再补......WA了一下午，晚上加了四行直接过了......

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <stack>
typedef double type;
using namespace std;
const double PI=acos(-1.0);
const double eps=1e-5;
const double inf=1e18;
struct Point
{
    type x,y;
    Point(){}
    Point(type a,type b)
    {
        x=a;
        y=b;
    }
    void read()
    {
        scanf("%lf%lf",&x,&y);
    }
    void print()
    {
        printf("%.6lf %.6lf\n",x,y);
    }

};
typedef Point Vector;
Vector operator + (Vector A,Vector B)
{
    return Vector(A.x+B.x,A.y+B.y);
}
Vector operator - (Point A,Point B)
{
    return Vector(A.x-B.x,A.y-B.y);
}
Vector operator * (Vector A,type p)
{
    return Vector(A.x*p,A.y*p);
}
Vector operator / (Vector A,type p)
{
    return Vector(A.x/p,A.y/p);
}
bool operator < (const Point &a,const Point &b)
{
   return a.x<b.x;
   // return a.x<b.x || (a.x==b.x && a.y<b.y);
}

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;
}
//atan2(x,y) :向量(x,y)的极角，即从x轴正半轴旋转到该向量方向所需要的角度。
type Dot(Vector A,Vector B)
{
    return A.x*B.x+A.y*B.y;
}
type Cross(Vector A,Vector B)
{
    return A.x*B.y-A.y*B.x;
}
type Length(Vector A)
{
    return sqrt(Dot(A,A));
}
type Angle(Vector A,Vector B)
{
    return acos(Dot(A,B))/Length(A)/Length(B);
}

type Area2(Point A,Point B,Point C)
{
    return Cross(B-A,C-A);
}
Vector Rotate(Vector A,double rad)
{
    return Vector(A.x*cos(rad)-A.y*sin(rad),A.x*sin(rad)+A.y*cos(rad));
}

Vector Normal(Vector A)//单位法线,左转90度，长度归一
{
    double L=Length(A);
    return Vector(-A.y/L,A.x/L);
}

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;
}
const int maxn=500050;
int n,m;
Point p[maxn];
int lt[maxn],rt[maxn];
struct query
{
    double x;
    int id;
}qy[maxn];
bool cmpx(query a,query b)
{
    return a.x<b.x;
}
bool cmpid(query a,query b)
{
    return a.id<b.id;
}
struct node
{
    int x;
    double pos;
    node(int xx,double y)
    {
        x=xx;
        pos=y;
    }
    node()
    {

    }
};
int main()
{
//    freopen("in.txt","r",stdin);
    int tt;
    int cnt=0;
    scanf("%d",&tt);
    while(tt--)
    {
        memset(lt,-1,sizeof lt);
        memset(rt,-1,sizeof rt);
        scanf("%d",&n);
        for (int i=0; i<n; i++)
        p[i].read();
        sort(p,p+n);

        scanf("%d",&m);
        for (int i=0; i<m; i++)
        {
            scanf("%lf",&qy[i].x);
            qy[i].id=i;
        }
        sort(qy,qy+m,cmpx);

        stack<node> s;
        while(!s.empty()) s.pop();


        int i=-1,j=0;
        Point ins;

        for (j=0; j<m; j++)
        {
            double v=qy[j].x;
            int id;
            while (i+1<n && dcmp(p[i+1].x-v)==-1)
            {
                i++;
                while(!s.empty())
                {
                    id=s.top().x;
                    if (dcmp(p[id].y-p[i].y)!=1) s.pop();
                    else break;
                }

                if (s.empty())
                {
                    s.push(node(i,inf));
                }
                else
                {

                    while(!s.empty())
                    {
                        id=s.top().x;
                        Point p1=p[id];
                        Vector v1=p[i]-p[id];
                        Point p2=Point(p[id].x,0);
                        Vector v2=Vector(1,0);
                        ins=GetLineIntersection(p1,v1,p2,v2);
                        if (ins.x<s.top().pos) break;
                        else s.pop();
                    }
                    s.push(node(i,ins.x));
                }
            }

            id=qy[j].id;
            while(!s.empty())
            {
                if (dcmp(s.top().pos-v)==1)
                {
                    lt[id]=s.top().x;
                    break;
                }
                else s.pop();
            }

            if (s.empty())
            {
                lt[id]=-1;
            }
        }

        while(!s.empty()) s.pop();

        i=n;
        for (j=m-1; j>=0; j--)
        {
            double v=qy[j].x;

            int id;
            while(i-1>=0 && dcmp(p[i-1].x-v)==1)
            {
                i--;
                while(!s.empty())
                {
                    id=s.top().x;
                    if (dcmp(p[id].y-p[i].y)!=1)s.pop();
                    else break;
                }
                if (s.empty())
                {
                        s.push(node(i,-inf));
                }
                else
                {
                    while(!s.empty())
                    {
                        id=s.top().x;
                        Point p1=p[id];
                        Vector v1=p[i]-p[id];
                        Point p2=Point(p[id].x,0);
                        Vector v2=Vector(-1,0);
                        ins=GetLineIntersection(p1,v1,p2,v2);
                        if (ins.x>s.top().pos) break;
                        else s.pop();
                    }
                    s.push(node(i,ins.x));
                }
            }
            id=qy[j].id;
            while(!s.empty())
            {
                if (dcmp(s.top().pos-v)==-1)
                {
                    rt[id]=s.top().x;
                    break;
                }
                else s.pop();
            }
            if (s.empty()) rt[id]=-1;
        }

        printf("Case #%d:\n",++cnt);
        sort(qy,qy+m,cmpid);
        for (int i=0; i<m; i++)
        {
            double a1,a2;
            Vector v1,v2;
            v2=Vector(0.0,1.0);
            if (lt[i]==-1) a1=90.0;
            else
            {
                v1=p[lt[i]]-Point(qy[i].x,0);
                v1=v1/Length(v1);
                a1=Angle(v1,v2)*180.0/PI;
            }
            if (rt[i]==-1) a2=90.0;
            else
            {
                v1=p[rt[i]]-Point(qy[i].x,0);
                v1=v1/Length(v1);
                a2=Angle(v1,v2)*180.0/PI;
            }
            printf("%.12lf\n",a1+a2);
        }
    }

    return 0;
}