func_code_string: #include <bits/stdc++.h>   using namespace std;   const double eps = 1e-8;   bool check(int n, int l, int v1, int v2, int k, double mid) {     double t0 = (l - v2 * mid) / (v1 - v2);     if (t0 < -eps) return 0;     double tb = mid - t0;     if (tb < -eps) return 0;     double tback = (v2 - v1) * tb / (v2 + v1) + tb;     if (tback + eps < tb) return 0;     return (n - 1) / k * tback + tb < mid + eps &&            (n - 1) / k * (tb - tback) * v2 + tb * v2 < l + eps;   }   int main() {     int n, l, v1, v2, k;     scanf( %d%d%d%d%d , &n, &l, &v1, &v2, &k);     double ll = 0, rr = 1. * l / v1;     for (int i = 1; i <= 100000; i++) {       double mid = (ll + rr) / 2;       if (check(n, l, v1, v2, k, mid))         rr = mid;       else         ll = mid;     }     printf( %.10f , ll);   }   