Language: C++

#include<bits/stdc++.h>
using namespace sdt;
int main(){
  int N;
  cin>>N;
  vector<int>a(N);
  vector<int>mark(9);
  for(int i=0;i<N;i++){
    cin>>a.at(i);
    int A=a.at(i);
    if(A/400<8){
      if(mark.at(A/400)==0){
        mark.at(A/400)=1;
      }
    }
    else{
      mark.at(8)=mark.at(8)+1;
    }
  }
  int sum=0;
  for(int i=0;i<9;i++){
    sum=sum+mark.at(i);
  }
  cout<<min(sum,8)<<endl;
}

Compiler output:
a.cc:2:17: error: 'sdt' is not a namespace-name
    2 | using namespace sdt;
      |                 ^~~
a.cc: In function 'int main()':
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin>>N;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146,
                 from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:3: error: 'vector' was not declared in this scope
    6 |   vector<int>a(N);
      |   ^~~~~~
a.cc:6:3: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from /usr/include/c++/14/functional:64,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:53:
/usr/include/c++/14/bits/stl_vector.h:428:11: note:   'std::vector'
  428 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
/usr/include/c++/14/vector:93:13: note:   'std::pmr::vector'
   93 |       using vector = std::vector<_Tp, polymorphic_allocator<_Tp>>;
      |             ^~~~~~
a.cc:6:10: error: expected primary-expression before 'int'
    6 |   vector<int>a(N);
      |          ^~~
a.cc:7:10: error: expected primary-expression before 'int'
    7 |   vector<int>mark(9);
      |          ^~~
a.cc:9:10: error: 'a' was not declared in this scope
    9 |     cin>>a.at(i);
      |          ^
a.cc:12:10: error: 'mark' was not declared in this scope
   12 |       if(mark.at(A/400)==0){
      |          ^~~~
a.cc:17:7: error: 'mark' was not declared in this scope
   17 |       mark.at(8)=mark.at(8)+1;
      |       ^~~~
a.cc:22:13: error: 'mark' was not declared in this scope
   22 |     sum=sum+mark.at(i);
      |             ^~~~
a.cc:24:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   24 |   cout<<min(sum,8)<<endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:24:9: error: 'min' was not declared in this scope; did you mean 'std::min'?
   24 |   cout<<min(sum,8)<<endl;
      |         ^~~
      |         std::min
In file included from /usr/include/c++/14/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51:
/usr/include/c++/14/bits/stl_algo.h:5696:5: note: 'std::min' declared here
 5696 |     min(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
a.cc:24:21: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   24 |   cout<<min(sum,8)<<endl;
      |                     ^~~~
      |                     std::endl
In file included from /usr/include/c++/14/istream:41,
                 from /usr/include/c++/14/sstream:40,
                 from /usr/include/c++/14/complex:45,
                 from /usr/include/c++/14/ccomplex:39,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:127:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~