func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, a, flag = 0;     vector<int> A, B;     map<int, int> store;     store.clear();     scanf( %d , &n);     for (int i = 0; i < n; i++) {       scanf( %d , &a);       if (store[a] < 2) {         if (store[a] == 0) {           A.push_back(a);           store[a] = 1;         } else {           flag = 1;           B.push_back(a);           store[a] = 2;         }       }     }     sort(A.begin(), A.end());     sort(B.begin(), B.end());     reverse(B.begin(), B.end());     int ans = A.size() + B.size();     if (flag)       if (A[A.size() - 1] == B[0]) ans--;     cout << ans << endl;     for (int i = 0; i < A.size(); i++) {       cout << A[i] <<    ;     }     for (int i = 0; i < B.size(); i++) {       if (i == 0 && B[i] == A[A.size() - 1]) continue;       cout << B[i] <<    ;     }     cout << endl;     return 0;   }   