Language: C++

#include<bits/stdc++.h>
int main(int argc, const char** argv) {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int i;

    string s,t;
    for(i=0;i<(int)s.length();++i){
    	if(s[i] != t[i])
    		break;
    }
    if((int)t.length() != (int)s.length() +1){
    	cout<<"No\n";
    	return 0;
    }

    if(i != (int)s.length())
    	cout<<"No\n";
    else
    	cout<<"Yes\n";

    return 0;
}

Compiler output:
a.cc: In function 'int main(int, const char**)':
a.cc:3:5: error: 'ios' has not been declared
    3 |     ios::sync_with_stdio(false);
      |     ^~~
a.cc:4:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    4 |     cin.tie(nullptr);
      |     ^~~
      |     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:8:5: error: 'string' was not declared in this scope
    8 |     string s,t;
      |     ^~~~~~
a.cc:8:5: 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:
/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:9:20: error: 's' was not declared in this scope
    9 |     for(i=0;i<(int)s.length();++i){
      |                    ^
a.cc:10:20: error: 't' was not declared in this scope
   10 |         if(s[i] != t[i])
      |                    ^
a.cc:13:13: error: 't' was not declared in this scope
   13 |     if((int)t.length() != (int)s.length() +1){
      |             ^
a.cc:13:32: error: 's' was not declared in this scope
   13 |     if((int)t.length() != (int)s.length() +1){
      |                                ^
a.cc:14:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   14 |         cout<<"No\n";
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:18:18: error: 's' was not declared in this scope
   18 |     if(i != (int)s.length())
      |                  ^
a.cc:19:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   19 |         cout<<"No\n";
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:21:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   21 |         cout<<"Yes\n";
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~