func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   string s;   vector<int> pos[26];   int xd[26];   int main() {     cin >> s;     n = s.size();     for (int i = 0; i < n; i++) {       pos[s[i] -  a ].push_back(i);       xd[s[i] -  a ]++;     }     double ans = 0;     for (char c =  a ; c <=  z ; c++) {       int best = 0;       for (int shift = 0; shift < n; shift++) {         vector<int> cnt(26, 0);         for (int i : pos[c -  a ]) {           cnt[s[(i + shift) % n] -  a ]++;         }         int nunique = 0;         for (int i = 0; i < 26; i++) {           if (cnt[i] == 1) {             nunique++;           }         }         best = max(best, nunique);       }       ans += 1.0 * best / n;     }     printf( %.10lf n , ans);     return 0;   }   