func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2e5 + 7;   map<long long, int> cnt;   bool vis[N];   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int n;     cin >> n;     long long a[n];     memset(vis, 0, sizeof(vis));     for (int i = 0; i < n; i++) {       long long x;       cin >> x;       while (1) {         auto it = cnt.find(x);         if (it == cnt.end()) {           cnt[x] = i;           break;         } else {           vis[cnt[x]] = true;           cnt.erase(it);           x *= 2LL;         }       }       a[i] = x;     }     vector<long long> vec;     for (int i = 0; i < n; i++) {       if (vis[i]) continue;       vec.push_back(a[i]);     }     cout << vec.size() << endl;     for (long long x : vec) cout << x <<    ;     cout << endl;     return 0;   }   