1 #include <cstdio> 2 #include <cstring> 3 #include <cmath> 4 #include <algorithm> 5 using namespace std; 6 const double pi=acos(-1.0); 7 const double eps=1e-6; 8 const double g=9.8; 9 10 int t;11 double h,v;12 double ok(double x)13 {14      double xx=((double)(x/180))*pi;15      double t1=v*sin(xx)/g;16      double y=v*t1*sin(xx)-0.5*g*t1*t1;17      double yy=y+h;18      double t2=sqrt(yy*2/g);19      double s=v*cos(xx)*(t1+t2);20      return s;21 }22 23 int main()24 {25     scanf("%d",&t);26     while(t--)27     {28         scanf("%lf%lf",&h,&v);29         double l=0,r=90;30         double c;31         while(r-l>eps)32         {33              double mid1=(r+l)/2;34              double mid2=(l+mid1)/2;35              if(ok(mid1)>=ok(mid2))36              {37                  c=mid1;38                  l=mid2;39              }40              else41                 r=mid1;42         }43         printf("%.2lf\n",ok(c));44     }45     return 0;46 }