func_code_string: #include <bits/stdc++.h>   using namespace std;   string s;   int n, i, j, k, mx = 0, sum = 0, vis[5005], letter[26], check[26][5005][26], ok;   double ans = 0;   int main() {     cin >> s;     n = s.length();     s = s + s;     for (i = 0; i < n; i++) {       letter[s[i] -  a ]++;       for (j = i; j < i + n; j++) {         check[s[i] -  a ][j - i + 1][s[j] -  a ]++;       }     }     for (i = 0; i < 26; i++) {       if (!letter[i]) continue;       mx = -1;       for (j = 2; j <= n; j++) {         sum = 0;         for (k = 0; k < 26; k++)           if (check[i][j][k] == 1) sum += 1;         mx = max(mx, sum);       }       ans += 1.0 * mx / n;     }     printf( %lf , ans);     return 0;   }   