HDU 5954 Do Not Pour Out

 #include<bits/stdc++.h>
 using namespace std;
 #define rep(i,a,b) for(int i=a;i<=b;++i)
 #define ms(arr,a) memset(arr,a,sizeof arr)
 #define debug(x) cout<<"< "#x" = "<<x<<" >"<<endl
 double eps=1e-;
 const double pi=3.1415926536;
 double d;
 double V;
 double longaxis,shortaxis;
 double calcV(double w)
 {
     if(w>-eps&&w<eps)return ;
     return (w-)*pi/w-(*(w-)*asin(-w)+sqrt(*w-w*w)*(-*w*w+*w-))//w;
 }
 bool ok(double w)
 {
     //debug(w);
     //debug(calcV(w));
     if(calcV(w)<V+eps)return true;
     return false;
 }
 double solve(double l,double r)
 {
     double m;
     while(l<r)
     {
         m=(l+r)/.;
         if(ok(m))l=m+eps;
         else r=m-eps;
     }
     return l;
 }
 double F(double x)
 {
     return *shortaxis/longaxis*(longaxis*longaxis*asin(x/longaxis)+sqrt(longaxis*longaxis-x*x)*x)/;
 }
 int main()
 {
     //freopen("Input.txt","r",stdin);
     //freopen("Output.txt","w",stdout);
     int T;scanf("%d",&T);
     while(T--)
     {
         scanf("%lf",&d);
         if(d>=)
         {
             printf("%.5f\n",pi*sqrt(d*d-*d+));
             continue;
         }
         if(d==)
         {
             printf("0.00000\n");
             continue;
         }
         V=d*pi;
         //debug(V);
         double w=solve(.,.);
         //debug(w);
         longaxis=sqrt(w*w+)/w;
         shortaxis=;
         double part=sqrt(w*w+);
         printf("%.5f\n",F(longaxis)-F(longaxis-part));
     }
     //freopen("CON","w",stdout);
     //system("start Output.txt");
 }