#10017 传送带（SCOI 2010）（三分套三分）

 1 #include <bits/stdc++.h>
 2 #define eps 1e-4
 3 using namespace std;
 4 int ax,ay,bx,by;
 5 int cx,cy,dx,dy;
 6 int p,q,r;
 7 inline int read() {
 8     int x=0,f=1; char c=getchar();
 9     while(c<‘0‘||c>‘9‘){if(c==‘-‘) f=-1;c=getchar();}
10     while(c>=‘0‘&&c<=‘9‘){x=x*10+c-‘0‘;c=getchar();}
11     return x*f;
12 }
13 double dis(double x1,double y1,double x2,double y2) {
14     return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
15 }
16 double cal(double x,double y) {
17     double lx=cx,ly=cy,rx=dx,ry=dy;
18     double lmx,lmy,rmx,rmy,t1,t2;
19     while(fabs(lx-rx)>eps||fabs(ly-ry)>eps) {
20         lmx=lx+(rx-lx)/3,lmy=ly+(ry-ly)/3;
21         rmx=lx+(rx-lx)/3*2,rmy=ly+(ry-ly)/3*2;
22         t1=dis(x,y,lmx,lmy)/r+dis(lmx,lmy,dx,dy)/q;
23         t2=dis(x,y,rmx,rmy)/r+dis(rmx,rmy,dx,dy)/q;
24         if(t1>t2) lx=lmx,ly=lmy;
25         else rx=rmx,ry=rmy;
26     }
27     return dis(ax,ay,x,y)/p+dis(x,y,lmx,lmy)/r+dis(lmx,lmy,dx,dy)/q;
28 }
29 int main() {
30     ax=read(),ay=read(),bx=read(),by=read();
31     cx=read(),cy=read(),dx=read(),dy=read();
32     p=read(),q=read(),r=read();
33     double lx=ax,ly=ay,rx=bx,ry=by;
34     double lmx,lmy,rmx,rmy,t1,t2;
35     while(fabs(lx-rx)>eps||fabs(ly-ry)>eps) {
36         lmx=lx+(rx-lx)/3,lmy=ly+(ry-ly)/3;
37         rmx=lx+(rx-lx)/3*2,rmy=ly+(ry-ly)/3*2;
38         t1=cal(lmx,lmy),t2=cal(rmx,rmy);
39         if(t1>t2) lx=lmx,ly=lmy;
40         else rx=rmx,ry=rmy;
41     }
42     printf("%.2f\n",cal(lx,ly));
43     return 0;
44 }