首次 6 小時 獻給的半平面交
//
// GGGGGGGGGGGGG CCCCCCCCCCCCC AAA
// GGG::::::::::::G CCC::::::::::::C A:::A
// GG:::::::::::::::G CC:::::::::::::::C A:::::A
// G:::::GGGGGGGG::::G C:::::CCCCCCCC::::C A:::::::A
// G:::::G GGGGGG C:::::C CCCCCC A:::::::::A
//G:::::G C:::::C A:::::A:::::A
//G:::::G C:::::C A:::::A A:::::A
//G:::::G GGGGGGGGGGC:::::C A:::::A A:::::A
//G:::::G G::::::::GC:::::C A:::::A A:::::A
//G:::::G GGGGG::::GC:::::C A:::::AAAAAAAAA:::::A
//G:::::G G::::GC:::::C A:::::::::::::::::::::A
// G:::::G G::::G C:::::C CCCCCC A:::::AAAAAAAAAAAAA:::::A
// G:::::GGGGGGGG::::G C:::::CCCCCCCC::::C A:::::A A:::::A
// GG:::::::::::::::G CC:::::::::::::::C A:::::A A:::::A
// GGG::::::GGG:::G CCC::::::::::::C A:::::A A:::::A
// GGGGGG GGGG CCCCCCCCCCCCCAAAAAAA AAAAAAA
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <complex>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
#include <ctime>
using namespace std;
#ifdef DEBUG
#define VAR(a,b) decltype(b) a=(b)
#define debug(...) printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)
#define gettime() end\_time=clock();printf("now running time is %.7f\\n",(float)(end\_time - start\_time)/CLOCKS\_PER\_SEC);
#else
#define VAR(a,b) \_\_typeof(b) a=(b)
#define debug(...)
#define gettime()
#endif
typedef unsigned int uint;
typedef long long int Int;
typedef unsigned long long int UInt;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\\n")
#define I\_de(x,n)for(int i=0;i<n;i++)printf("%d ",x\[i\]);Pln()
#define De(x)printf(#x"%d\\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\\
printf("%d ",dp\[htx\]\[hty\]);}Pln();}
#define M 30005
#define PII pair<int,int\>
#define PB push\_back
#define oo INT\_MAX
#define Set\_oo 0x3f
#define FOR(a,b) for(VAR(a,(b).begin());a!=(b).end();++a)
#define eps 1e-6
clock\_t start\_time=clock(), end\_time;
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
bool xeqy(double x,double y){return fabs(x-y)<eps;}
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
typedef complex<double\> point;
struct line{
point a,b;
};
#define x real()
#define y imag()
typedef vector<point> poly;
double cross(point o,point a,point b){
// debug("po %lf %lf\\n",o.x,o.y);
return (a.x-o.x)\*(b.y-o.y)-(a.y-o.y)\*(b.x-o.x);
}
double cross(point a,point b){
return a.x\*b.y-a.y\*b.x;
}
double area(poly p){
double ar=0;
int size=p.size();
for(int i=0;i<size;i++){
// debug("%lf %lf\\n",p\[i\].x,p\[i\].y);
ar+=cross(p\[i\],p\[(i+1)%size\]);
}//Pln();
return fabs(ar)/2;
}
point intersection(point a1,point a2,point b1,point b2){
point a=a2-a1,b=b2-b1,s=b1-a1;
return a1+a\*cross(b,s)/cross(b,a);
}
poly halfplane(poly p,line& lin,int fg){
poly q;
point p1=lin.a,p2=lin.b;
int n=p.size();
for(int i=0;i<n;i++){
double c=cross(p1,p2,p\[i\]);
int t=(i+1)%n;
double d=cross(p1,p2,p\[t\]);
// debug("%lf %lf\\n",c,d);
if(c\*fg>=0)q.PB(p\[i\]);
if(c\*d<0)q.PB(intersection(p1,p2,p\[i\],p\[t\]));
}
return q;
}
double lx,ly,nx,ny;
char cmd\[50\];
poly p;
void init(){
p.PB(point(0.0,0.0));
p.PB(point(10.0,0.0));
p.PB(point(10.0,10.0));
p.PB(point(0.0,10.0));
}
int main() {
ios\_base::sync\_with\_stdio(0);
lx=ly=0.0;
init();
bool isover=false;
while(~scanf("%lf%lf%s",&nx,&ny,cmd)){
line l;
int fg=1;
point cm=point((nx+lx)/2,(ny+ly)/2);
point acm=point(cm.x-ly+ny,cm.y+lx-nx);
if(!strcmp(cmd,"Same")){
p.clear();
}else if(!strcmp(cmd,"Hotter")){
if(cross(acm-cm,point(lx-cm.x,ly-cm.y))>0){
fg=-1;
}
}else{
if(cross(acm-cm,point(lx-cm.x,ly-cm.y))<0){
fg=-1;
}
}
l.a=cm;
l.b=acm;
p=halfplane(p,l,fg);
printf("%.2f\\n",area(p));
lx=nx;ly=ny;
}
}