func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5000 + 100;   const int M = 30;   int n;   string s;   string t;   int mat[M][M][N];   int ones[N];   int ans;   long double javab;   set<char> g;   bool mark[30];   int chand[30];   bool oomade[30];   int main() {     cin >> s;     n = s.size();     for (int i = 0; i < n; i++) {       g.insert(s[i]);       chand[s[i] -  a ]++;       oomade[s[i] -  a ] = 1;     }     for (int i = 0; i < n; i++) {       for (int j = i + 1; j < n + i; j++) {         int y = j % n;         int f = (int)s[i] - (int) a ;         int l = (int)s[y] - (int) a ;         mat[f][l][j - i]++;       }     }     for (int i = 0; i < 26; i++) {       if (oomade[i] == 1) {         for (int j = 0; j < n; j++) {           int tmp = 0;           for (int k = 0; k < 26; k++) {             if (mat[i][k][j] == 1) {               tmp++;             }           }           ones[i] = max(ones[i], tmp);         }         ans += ones[i];       }     }     javab = (long double)ans / (n);     cout << fixed << setprecision(10) << javab;   }   