View Compilation Error

0_0_39289599_12049.cpp:6:1: error: 'vector' does not name a type
    6 | vector<int> v;
      | ^~~~~~
0_0_39289599_12049.cpp:10:1: error: 'vector' does not name a type
   10 | vector<node> v2;
      | ^~~~~~
0_0_39289599_12049.cpp: In function 'int main()':
0_0_39289599_12049.cpp:16:5: error: 'v' was not declared in this scope
   16 |     v.push_back(0);
      |     ^
0_0_39289599_12049.cpp:24:9: error: 'v2' was not declared in this scope
   24 |         v2.push_back(m);
      |         ^~
0_0_39289599_12049.cpp:26:10: error: 'v2' was not declared in this scope
   26 |     sort(v2.begin(),v2.end(),cmp);
      |          ^~