func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int tt;     cin >> tt;     while (tt--) {       int n, l;       cin >> n >> l;       vector<double> flags(n);       for (auto& i : flags) cin >> i;       double a_s = 0, b_s = l;       double a_v = 1, b_v = 1;       int a_i = 0, b_i = n - 1;       double t = 0;       for (;;) {         double a_d = a_i < n ? flags[a_i] - a_s : 1e300,                b_d = b_i >= 0 ? b_s - flags[b_i] : 1e300;         double a_t = a_d / a_v, b_t = b_d / b_v;         double sep = b_s - a_s;         double sep_t = sep / (a_v + b_v);         double mn = min({a_t, b_t, sep_t});         t += mn;         a_s += a_v * mn;         b_s -= b_v * mn;         if (a_t == mn) {           a_v++;           a_i++;         } else if (b_t == mn) {           b_v++;           b_i--;         } else           break;       }       cout << fixed << t << endl;     }   }   