func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     string s;     cin >> s;     int fre[26] = {0};     for (int i = 0; i < n; i++) {       fre[s[i] -  a ] = fre[s[i] -  a ] + 1;     }     string ans =   ;     for (int i = 0; i < 26; i++) {       for (int j = 0; j < fre[i]; j++) {         ans = ans + char(97 + i);       }     }     cout << ans;   }   