func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e5 + 100;   int a[N];   int main() {     ios_base::sync_with_stdio(false);     int n, U;     cin >> n >> U;     for (int i = 1; i <= n; ++i) cin >> a[i];     double ans = -1;     for (int i = 1, j = 1; i + 1 <= n; ++i) {       while (j + 1 <= n and a[j + 1] - a[i] <= U) ++j;       if (j - i + 1 < 3) continue;       ans = max(ans, (double)(a[j] - a[i + 1]) / (a[j] - a[i]));     }     cout << fixed << setprecision(9) << ans <<   n ;   }   