Eroare de compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:42: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void write()’: user.cpp:50: error: no match for ‘operator<’ in ‘g.std::basic_ofstream<char, std::char_traits<char> >::<anonymous>.std::basic_ostream<_CharT, _Traits>::operator<< [with _CharT = char, _Traits = std::char_traits<char>](sol[i]) < " "’ user.cpp:50: note: candidates are: operator<(const char*, const char*) <built-in> user.cpp:50: note: operator<(void*, void*) <built-in>