func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long int n, k;     cin >> n >> k;     long long int arr[n];     map<long long int, bool> mp;     deque<long long int> dq;     for (long long int i = 0; i < n; i++) {       cin >> arr[i];       mp[arr[i]] = false;     }     for (long long int i = 0; i < n; i++) {       if (!mp[arr[i]]) {         mp[arr[i]] = true;         if (dq.size() == k) {           mp[dq.back()] = false;           dq.pop_back();         }         dq.push_front(arr[i]);       }     }     cout << dq.size() << endl;     for (auto x : dq) {       cout << x <<    ;     }     cout << endl;   }   