func_code_string: #include <bits/stdc++.h>   using namespace std;   namespace WorkSpace {   const double pi = acos(-1.0);   int N;   double r, v;   bool Check(double mid, double l) {     double len = 2 * pi * r;     double ang = mid / len * 2 * pi;     double A = r - r * (cos(ang));     double B = r * sin(ang);     return sqrt(A * A + B * B) + mid > l;   }   void Deal(double s, double t) {     double l = 0, r = t - s;     double mid;     int Cnt = 0;     while (Cnt <= 40) {       ++Cnt;       mid = (l + r) / 2;       if (Check(mid, t - s))         r = mid;       else         l = mid;     }     printf( %.10lf n , l / v);   }   void Main() {     scanf( %d%lf%lf , &N, &r, &v);     while (N--) {       double s, t;       scanf( %lf%lf , &s, &t);       Deal(s, t);     }     return;   }   }  // namespace WorkSpace   int main() { WorkSpace ::Main(); }   