Language: C++

#include <iostream>
#include <string>

using namespace std::

int main(){
  string s;
  cin>> s;
  
  if(s=="Sunny") cout<< "Cloudy" <<endl;
  if(s=="Cloudy") cout<< "Rainy" <<endl;
  if(s=="Rainy") cout<< "Sunny" <<endl;

}

Compiler output:
a.cc:6:1: error: expected identifier before 'int'
    6 | int main(){
      | ^~~
a.cc:4:22: error: expected ';' before 'int'
    4 | using namespace std::
      |                      ^
      |                      ;
    5 | 
    6 | int main(){
      | ~~~                   
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/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/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:8:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    8 |   cin>> s;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:8:9: error: 's' was not declared in this scope
    8 |   cin>> s;
      |         ^
a.cc:10:18: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   10 |   if(s=="Sunny") cout<< "Cloudy" <<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:10:36: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   10 |   if(s=="Sunny") cout<< "Cloudy" <<endl;
      |                                    ^~~~
      |                                    std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:11:19: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   11 |   if(s=="Cloudy") cout<< "Rainy" <<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:11:36: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   11 |   if(s=="Cloudy") cout<< "Rainy" <<endl;
      |                                    ^~~~
      |                                    std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
a.cc:12:18: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   12 |   if(s=="Rainy") cout<< "Sunny" <<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:12:35: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
   12 |   if(s=="Rainy") cout<< "Sunny" <<endl;
      |                                   ^~~~
      |                                   std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~