Language: C++

#include <bits/stdc++.h>

int main(){

  int a;
  int b;
  string s;
  bool check = true;

  cin >> a >> b >> s;

  for(int i = 0;i < s.size();i++){
    if(i == a){
      // if(s[i+1] == '-'){
        if(s[i] == '-'){
        check = true;
      }else if(s[i] >= "0" && s[i] <= "9"){
        check = true;
      }
    }

    if(check == true){
      cout << "YES" << endl;
    }else{
      cout << "NO" << endl;
    }

    return 0;
  }
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:3: error: 'string' was not declared in this scope
    7 |   string s;
      |   ^~~~~~
a.cc:7:3: note: suggested alternatives:
In file included from /usr/include/c++/14/string:41,
                 from /usr/include/c++/14/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:52,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:10:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
   10 |   cin >> a >> b >> s;
      |   ^~~
      |   std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:146:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:10:20: error: 's' was not declared in this scope
   10 |   cin >> a >> b >> s;
      |                    ^
a.cc:23:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   23 |       cout << "YES" << 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:23:24: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   23 |       cout << "YES" << 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)
      |     ^~~~
a.cc:25:7: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   25 |       cout << "NO" << 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:25:23: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   25 |       cout << "NO" << endl;
      |                       ^~~~
      |                       std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~