HDU3400+三分

三分出两个中间的位置即可。

/*
两次三分
*/
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
#include<algorithm>
using namespace std;
const int maxn = 105;
const double eps = 1e-8;
const double pi = acos(-1.0);
struct Point {
    double x,y;
};
Point a,b,c,d;
double P,Q,R,ans1,ans2;

double dis( Point aa,Point bb ){
    return sqrt( (aa.x-bb.x)*(aa.x-bb.x)+(aa.y-bb.y)*(aa.y-bb.y) );
}

double GetAns( double tt1,double tt2 ){
    double ans;
    Point temp1,temp2;
    temp1.x = a.x+tt1*(b.x-a.x),temp1.y = a.y+tt1*(b.y-a.y);
    temp2.x = c.x+tt2*(d.x-c.x),temp2.y = c.y+tt2*(d.y-c.y);
    ans = dis( a,temp1 )/P+dis( temp1,temp2 )/R+dis( temp2,d )/Q;
    return ans;
}

double solve( double x ){
    double L,R,mid1,mid2;
    L = 0;
    R = 1;
    while( R-L>eps ){
        mid1 = (L+R)/2.0;
        mid2 = (mid1+R)/2.0;
        if( GetAns( x,mid1 )<GetAns( x,mid2 ) ){
            ans2 = mid1;
            R = mid2;
        }
        else{
            ans2 = mid2;
            L = mid1;
        }
    }
    return GetAns( x,ans2 );
}

int main(){
    int T;
    scanf("%d",&T);
    while( T-- ){
        scanf("%lf%lf%lf%lf",&a.x,&a.y,&b.x,&b.y);
        scanf("%lf%lf%lf%lf",&c.x,&c.y,&d.x,&d.y);
        scanf("%lf%lf%lf",&P,&Q,&R);
        double L,R,mid1,mid2;
        L = 0;
        R = 1;
        while( R-L>eps ){
            mid1 = (L+R)/2.0;
            mid2 = (mid1+R)/2.0;
            if( solve( mid1 )<solve( mid2 ) ){
                ans1 = mid1;
                R = mid2;
            }
            else{
                ans1 = mid2;
                L = mid1;
            }
        }
        printf("%.2lf
",GetAns( ans1,ans2 ));
    }
    return 0;
}