Language: C++

#include <bits/stdc++.h>

int main(){
	string s;
	cin >> s;
	map<char, char>m;
	m['D'] = 'A';
	m['E'] = 'B';
	m['F'] = 'C';
	m['G'] = 'D';
	m['H'] = 'E';
	m['I'] = 'F';
	m['J'] = 'G';
	m['K'] = 'H';
	m['L'] = 'I';
	m['M'] = 'J';
	m['N'] = 'K';
	m['O'] = 'L';
	m['P'] = 'M';
	m['Q'] = 'N';
	m['R'] = 'O';
	m['S'] = 'P';
	m['T'] = 'Q';
	m['U'] = 'R';
	m['V'] = 'S';
	m['W'] = 'T';
	m['X'] = 'U';
	m['Y'] = 'V';
	m['Z'] = 'W';
	m['A'] = 'X';
	m['B'] = 'Y';
	m['C'] = 'Z';
	for (int i = 0; i < s.size(); i++) {
		cout << m[s[i]];
	}
	cout << "\n";
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:9: error: 'string' was not declared in this scope
    4 |         string s;
      |         ^~~~~~
a.cc:4:9: 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:5:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |         cin >> 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:5:16: error: 's' was not declared in this scope
    5 |         cin >> s;
      |                ^
a.cc:6:9: error: 'map' was not declared in this scope
    6 |         map<char, char>m;
      |         ^~~
a.cc:6:9: note: suggested alternatives:
In file included from /usr/include/c++/14/map:63,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:152:
/usr/include/c++/14/bits/stl_map.h:102:11: note:   'std::map'
  102 |     class map
      |           ^~~
/usr/include/c++/14/map:89:13: note:   'std::pmr::map'
   89 |       using map
      |             ^~~
a.cc:6:13: error: expected primary-expression before 'char'
    6 |         map<char, char>m;
      |             ^~~~
a.cc:7:9: error: 'm' was not declared in this scope; did you mean 'tm'?
    7 |         m['D'] = 'A';
      |         ^
      |         tm
a.cc:34:17: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   34 |                 cout << m[s[i]];
      |                 ^~~~
      |                 std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:36:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
   36 |         cout << "\n";
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~