func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     int n, l;     cin >> n >> l;     vector<int> flags(n + 2);     flags[0] = 0, flags[n + 1] = l;     for (int i = 0; i < n; ++i) {       cin >> flags[i + 1];     }     vector<double> s(n + 2);     vector<double> e(n + 2);     s[0] = 0;     e[n + 1] = 0;     for (int i = 1; i < n + 2; ++i) {       s[i] = s[i - 1] + (flags[i] - flags[i - 1]) * 1.0 / i;       e[n - i + 1] =           e[n - i + 2] + (flags[n - i + 2] - flags[n - i + 1]) * 1.0 / (i);     }     for (int i = 0; i < n + 2; ++i) {       if (abs(s[i] - e[i]) < 1e-6) {         cout << s[i] <<   n ;         return;       } else if (s[i] > e[i]) {         double sspd = i;         double espd = n - i + 2;         double dist = flags[i] - flags[i - 1];         double result = espd * e[i] + sspd * s[i - 1] + dist;         result = result / (sspd + espd);         cout << result <<   n ;         return;       }     }   }   int main() {     cout << setprecision(9);     cout << fixed;     int tests;     cin >> tests;     while (tests) {       solve();       tests--;     }   }   