/in/foo.cc:1:1: error: 'vector' does not name a type
 vector<int> a;
 ^~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:6:5: error: 'cin' was not declared in this scope
     cin>>n;
     ^~~
/in/foo.cc:10:29: error: 'a' was not declared in this scope
         for(int i = 0 ; i < a.size() ; i++)
                             ^
/in/foo.cc:20:13: error: 'cout' was not declared in this scope
             cout<<t<<" ";
             ^~~~
/in/foo.cc:21:13: error: 'a' was not declared in this scope
             a.push_back(t);
             ^