Language: C++

#include<iostream>
#include<vector>
#include<string>
int main(){
int n,q;
  cin>>n>>q;
  string s;
  cin>>s;
  vector<int> a(n+1,0);
  for(int i=0;i<n;i++){
    if(i+1<n&&s[i]=='A'&&s[i+1]=='C') a[i+1]=a[i]+1;
    else a[i+1]=a[i];
  }
  
  for(int q=0;q<n;q++){
    int l,r;
    cin>>l>>r;
    --l;
    --r;
    cout<<s[r]-s[l]<<endl;
  }
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:6:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    6 |   cin>>n>>q;
      |   ^~~
      |   std::cin
In file included 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: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/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:8:8: error: 's' was not declared in this scope
    8 |   cin>>s;
      |        ^
a.cc:9:3: error: 'vector' was not declared in this scope
    9 |   vector<int> a(n+1,0);
      |   ^~~~~~
a.cc:9:3: note: suggested alternatives:
In file included from /usr/include/c++/14/vector:66,
                 from a.cc:2:
/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:9:10: error: expected primary-expression before 'int'
    9 |   vector<int> a(n+1,0);
      |          ^~~
a.cc:11:39: error: 'a' was not declared in this scope
   11 |     if(i+1<n&&s[i]=='A'&&s[i+1]=='C') a[i+1]=a[i]+1;
      |                                       ^
a.cc:12:10: error: 'a' was not declared in this scope
   12 |     else a[i+1]=a[i];
      |          ^
a.cc:20:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   20 |     cout<<s[r]-s[l]<<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:20:22: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   20 |     cout<<s[r]-s[l]<<endl;
      |                      ^~~~
      |                      std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~