foo.cc: In function 'int main()':
foo.cc:3:5: error: 'cin' was not declared in this scope
    3 |     cin>>t;
      |     ^~~
foo.cc:6:5: error: 'vector' was not declared in this scope
    6 |     vector<int>arr(n);
      |     ^~~~~~
foo.cc:6:12: error: expected primary-expression before 'int'
    6 |     vector<int>arr(n);
      |            ^~~
foo.cc:7:12: error: expected primary-expression before 'int'
    7 |     vector<int>ar2(n);
      |            ^~~
foo.cc:11:14: error: 'arr' was not declared in this scope
   11 |         cin>>arr[i];
      |              ^~~
foo.cc:12:14: error: 'ar2' was not declared in this scope
   12 |         cin>>ar2[i];
      |              ^~~
foo.cc:15:5: error: 'cout' was not declared in this scope
   15 |     cout<<min(arr.size(),ar2.size());
      |     ^~~~
foo.cc:15:15: error: 'arr' was not declared in this scope
   15 |     cout<<min(arr.size(),ar2.size());
      |               ^~~
foo.cc:15:26: error: 'ar2' was not declared in this scope
   15 |     cout<<min(arr.size(),ar2.size());
      |                          ^~~
foo.cc:15:11: error: 'min' was not declared in this scope; did you mean 'main'?
   15 |     cout<<min(arr.size(),ar2.size());
      |           ^~~
      |           main