func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string s;     cin >> s;     int cnt[26] = {0};     for (int i = 0; i < s.size(); i++) {       cnt[s[i] -  a ]++;     }     int ans[26] = {0};     vector<int> v;     for (int i = 0; i < 26; i++) {       ans[i] = cnt[i] / 2;       cnt[i] = cnt[i] % 2;       if (cnt[i] == 1) v.push_back(i);     }     for (int i = 0; i < v.size() / 2; i++) {       ans[v[i]]++;     }     int tmp = -1;     if (v.size() % 2 == 1) {       tmp = v[v.size() / 2];     }     for (int i = 0; i < 26; i++) {       for (int j = 0; j < ans[i]; j++) {         cout << (char)( a  + i);       }     }     if (tmp != -1) {       cout << (char)( a  + tmp);     }     for (int i = 25; i >= 0; i--) {       for (int j = 0; j < ans[i]; j++) {         cout << (char)( a  + i);       }     }     return 0;   }   