POJ 2540 Hotter Colder
线性规划？找每次的中垂线加进来一起做半平面交就好了。
[NOTICE] 出现same不一定为0，有可能两个点在同一个位置。计算几何注意考虑问题全面，重合什么的最讨厌了。
#include <algorithm>
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <map>
#include <set>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <string>
#include <bitset>
#include <memory>
#include <complex>
#include <numeric>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <ctype.h>
#include <locale.h>
using namespace std;
#pragma pack(4)
const double eps = 1e-8;
const double pi = acos(-1.0);
const int inf = 0x7f7f7f7f;
#define loop(a,n) \
for(int i=0;n>i;i++) \
cout<<a[i]<<(i!=n-1?' ':'\n')
#define loop2(a,n,m) \
for(int i=0;n>i;i++) \
for(int j=0;m>j;j++) \
cout<<a[i][j]<<(j!=m-1?' ':'\n')
#define at(a,i) ((a)&(1<<(i)))
#define nt(a,i) ((a)^(1<<(i)))
#define set1(a,i) ((a)|(1<<(i)))
#define set0(a,i) ((a)&(~(1<<(i))))
#define cmp(a,b) (fabs((a)-(b))<eps?0:(((a)-(b))>eps?+1:-1))
#define lmax(a,b) ((a)>(b)?(a):(b))
#define lmin(a,b) ((a)<(b)?(a):(b))
#define fmax(a,b) (cmp(a,b)>0?(a):(b))
#define fmin(a,b) (cmp(a,b)<0?(a):(b))
const int MAXV = 120;
typedef struct Point
{
double o[2];
double & operator [] (int i)
{
return o[i];
}
friend ostream & operator << (ostream & cout,Point argu)
{
return cout<<"("<<argu[0]<<","<<argu[1]<<")";
}
Point(double x=0,double y=0)
{
o[0]=x;
o[1]=y;
}
Point operator + (Point argu)
{
return Point(o[0]+argu[0],o[1]+argu[1]);
}
Point operator - (Point argu)
{
return Point(o[0]-argu[0],o[1]-argu[1]);
}
Point operator + (double argu)
{
return (*this)*(1+argu/length());
}
Point operator - (double argu)
{
return (*this)*(1-argu/length());
}
Point operator * (double argu)
{
return Point(o[0]*argu,o[1]*argu);
}
Point operator / (double argu)
{
return Point(o[0]/argu,o[1]/argu);
}
bool operator < (Point argu) const
{
if(cmp(o[0],argu[0])!=0) return cmp(o[0],argu[0])<0;
else return cmp(o[1],argu[1])<0;
}
bool operator == (Point argu) const
{
return cmp(o[0],argu[0])==0&&cmp(o[1],argu[1])==0;
}
double length(void)
{
return sqrt(o[0]*o[0]+o[1]*o[1]);
}
double angle(void)
{
return fmod(atan2(o[1],o[0])+2*pi,2*pi);
}
}Vector;
double dot(Vector a,Vector b)
{
return a[0]*b[0]+a[1]*b[1];
}
double dot(Point o,Point a,Point b)
{
return dot(a-o,b-o);
}
int ward(Point p,Point s,Point e)
{
return cmp(dot(s,e,p),0);
}
double cross(Vector a,Vector b)
{
return a[0]*b[1]-a[1]*b[0];
}
double cross(Point o,Point a,Point b)
{
return cross(a-o,b-o);
}
int side(Point p,Point s,Point e)
{
return cmp(cross(s,e,p),0);
}
double area(Point poly[],int n)
{
double ans=0;
for(int i=1;n>i+1;i++)
{
ans+=cross(poly[0],poly[i],poly[i+1]);
}
return abs(ans)/2;
}
int boundingBox(double x,double a,double b)
{
return cmp(a,x)*cmp(x,b);
}
int boundingBox(Point p,Point s,Point e)
{
if(boundingBox(p[0],s[0],e[0])>0&&boundingBox(p[1],s[1],e[1])>0) return 1;
else if(boundingBox(p[0],s[0],e[0])>=0&&boundingBox(p[1],s[1],e[1])>=0) return 0;
else return -1;
}
int locate(Point p,Point s,Point e)
{
if(p==s||p==e) return 0;
return side(p,s,e)==0&&boundingBox(p,s,e)>=0?1:-1;
}
int locate(Point p,Point poly[],int n)
{
int cnt[3]={0};
poly[n]=poly[0];
for(int i=0;n>i;i++)
{
cnt[side(p,poly[i],poly[i+1])+1]=true;
if(cnt[1]) return 0;
if(cnt[2]&&cnt[0]) return -1;
}
return 1;
}
int intersection(Point s1,Point e1,Point s2,Point e2)
{
if(side(s1,s2,e2)*side(e1,s2,e2)<0&&side(s2,s1,e1)*side(e2,s1,e1)<0) return 1;
else
{
if(locate(s1,s2,e2)>=0) return 0;
if(locate(e1,s2,e2)>=0) return 0;
if(locate(s2,s1,e1)>=0) return 0;
if(locate(e2,s1,e1)>=0) return 0;
return -1;
}
}
struct Line
{
Point s,e;
double o[3],angle;
double & operator [] (int i)
{
return o[i];
}
friend ostream & operator << (ostream & cout,Line argu)
{
return cout<<"["<<argu.s<<"->"<<argu.e<<"]";
return cout<<"["<<argu[0]<<","<<argu[1]<<" "<<argu[2]<<"]";
}
Line(Point s,Point e)
{
this->s=s;
this->e=e;
o[0]=s[1]-e[1];
o[1]=e[0]-s[0];
o[2]=cross(s,e);
angle=(e-s).angle();
}
Line(double a=0,double b=0,double c=1)
{
o[0]=a;
o[1]=b;
o[2]=c;
if(cmp(a,0)!=0)
{
s=Point(-c/a,0);
e=s+dir();
}
else if(cmp(b,0)!=0)
{
s=Point(0,-c/b);
e=s+dir();
}
angle=(e-s).angle();
}
Line operator + (double argu)
{
return Line(s+pen()*argu/pen().length(),e+pen()*argu/pen().length());
}
Line operator - (double argu)
{
return Line(s-pen()*argu/pen().length(),e-pen()*argu/pen().length());
}
bool operator < (Line argu) const
{
if(cmp(angle,argu.angle)!=0) return cmp(angle,argu.angle)<0;
else return side(argu.s,s,e)<0;
}
bool operator == (Line argu) const
{
return cmp(angle,argu.angle)==0;
}
Vector dir(void) const
{
return Vector(o[1],-o[0]);
}
Vector pen(void) const
{
return Vector(o[0],+o[1]);
}
};
int ward(Point p,Line l)
{
return ward(p,l.s,l.e);
}
int side(Point p,Line l)
{
return side(p,l.s,l.e);
}
#ifndef SPECIAL
#define SPECIAL
Point solve(double a1,double b1,double c1,double a2,double b2,double c2)
{
Point A(a1,a2);
Point B(b1,b2);
Point R(c1,c2);
return Point(cross(R,B),cross(A,R))/cross(B,A);
}
Point meet(Line a,Line b)
{
return solve(a[0],a[1],a[2],
b[0],b[1],b[2]);
}
Point foot(Point p,Line l)
{
return solve(l[0],l[1],l[2],
l[1],-l[0],l[0]*p[1]-l[1]*p[0]);
}
Point symmetry(Point p,Line l)
{
return solve(l[0],l[1],l[0]*p[0]+l[1]*p[1]+2*l[2],
l[1],-l[0],l[0]*p[1]-l[1]*p[0]);
}
#endif // SPECIAL
#ifndef DIS
#define DIS
double dis(Point a,Point b)
{
return (b-a).length();
}
double disPar(Point p,Line l)
{
return dot(l.s,l.e,p)/dis(l.s,l.e);
}
double disPen(Point p,Line l)
{
return cross(l.s,l.e,p)/dis(l.s,l.e);
}
double dis(Point p,Point s,Point e)
{
if(ward(p,s,e)*ward(p,e,s)>0) return disPen(p,Line(s,e));
else return fmin(dis(p,s),dis(p,e));
}
double dis(Line a,Line b)
{
if(cmp(a.angle,b.angle)!=0) return 0;
else return disPen(a.s,b);
}
double dis(Line l,Point s,Point e)
{
if(side(s,l)*side(e,l)<0) return 0;
else return fmin(disPen(s,l),disPen(e,l));
}
double dis(Point s1,Point e1,Point s2,Point e2)
{
if(intersection(s1,e1,s2,e2)>=0) return 0;
else return fmin(fmin(dis(s1,s2,e2),dis(e1,s2,e2)),fmin(dis(s2,s1,e1),dis(e2,s1,e1)));
}
#endif // DIS
int n=0;
double x,y;
char o[12];
Line l[MAXV],plane[MAXV];
Point p[MAXV],convex[MAXV];
int HPI()
{
int f=0,r=-1;
n=(sort(l,l+n),unique(l,l+n))-l;
for(int i=0;n>i;i++)
{
while(f<r&&side(meet(plane[r-1],plane[r]),l[i])<0) r--;
while(f<r&&side(meet(plane[f+1],plane[f]),l[i])<0) f++;
plane[++r]=l[i];
}
while(f<r&&side(meet(plane[r-1],plane[r]),plane[f])<0) r--;
while(f<r&&side(meet(plane[f+1],plane[f]),plane[r])<0) f++;
int cnt=0;
for(int i=f;i<r;i++)
{
convex[cnt++]=meet(plane[i],plane[i+1]);
}
convex[cnt++]=meet(plane[f],plane[r]);
return cnt;
}
Point A( 0, 0);
Point B(10, 0);
Point C(10,10);
Point D( 0,10);
int main()
{
#ifndef ONLINE_JUDGE
freopen("Hotter Colder.txt","r",stdin);
#else
#endif
l[n++]=Line(A,B);
l[n++]=Line(B,C);
l[n++]=Line(C,D);
l[n++]=Line(D,A);
Point prev(0,0);
bool flag=false;
while(scanf("%lf %lf %s",&x,&y,o)!=EOF)
{
Point now(x,y);
if(!strcmp(o,"Colder"))
{
l[n++]=Line((now+prev)/2,(now+prev)/2+Line(prev,now).pen());
}
else if(!strcmp(o,"Hotter"))
{
l[n++]=Line((now+prev)/2,(now+prev)/2-Line(prev,now).pen());
}
else
{
if(prev==now);
else flag=true;
}
printf("%.2f\n",flag?0:area(convex,HPI()));
prev=now;
}
return 0;
}