Eroare de compilare: main.cpp: In function 'void solve()': main.cpp:27:6: error: no match for 'operator<<' (operand types are 'std::ifstream' {aka 'std::basic_ifstream<char>'} and 'char') 27 | f<<'\n'; | ~^~~~~~ | | | | | char | std::ifstream {aka std::basic_ifstream<char>} main.cpp:27:6: note: candidate: 'operator<<(int, int)' (built-in) 27 | f<<'\n'; | ~^~~~~~ main.cpp:27:6: note: no known conversion for argument 1 from 'std::ifstream' {aka 'std::basic_ifstream<char>'} to 'int' In file included from /usr/include/c++/10/regex:62, from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:110, from main.cpp:1: /usr/include/c++/10/bits/regex.h:1647:5: note: candidate: 'template<class _Ch_type, class _Ch_traits, class _Bi_iter> std::basic_ostream<_CharT, _Traits>& std::__cxx11::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::sub_match<_Bi_iter>&)' 1647 | operator<<(basic_ostream<_Ch_type, _Ch_traits>& __os, | ^~~~~~~~ /usr/include/c++/10/bits/regex.h:1647:5: note: template argument deduction/substitution failed: main.cpp:27:8: note: 'std::ifstream' {aka 'std::basic_ifstream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>' 27 | f<<'\n'; | ^~~~ In file included from /usr/include/c++/10/string:55, from /usr/include/c++/10/bits/locale_classes.h:40, from /usr/include/c++/10/bits/ios_base.h:41, from /usr/include/c++/10/ios:42, from /usr/include/c++/10/istream:38, from /usr/include/c++/10/sstream:38, from /usr/include/c++/10/complex:45, from /usr/include/c++/10/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54, from main.cpp:1: /usr/include/c++/10/bits/basic_string.h:6468:5: note: candidate: 'template<class _CharT, class _Traits, class _Alloc> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&)' 6468 | operator<<(basic_ostream<_CharT, _Traits>& __os, | ^~~~~~~~ /usr/include/c++/10/bits/basic_string.h:6468:5: note: template argument deduction/substitution failed: main.cpp:27:8: note: 'std::ifstream' {aka 'std::basic_ifstream<char>'} is not derived from 'std::basic_ostream<_CharT, _Traits>' 27 | f<<'\n'; | ^~~~ In file included from /usr/include/c++/10/bits/ios_base.h:46, from /usr/include/c++/10/ios:42, from /usr/include/c++/10/istream:38, from /usr/include/c++/10/sstream:38, from /usr/include/c++/10/complex:45, from /usr/include/c++/10/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54, from main.cpp:1: /usr/include/c++/10/system_error:262:5: note: candidate: 'template<class _CharT, class _Traits> std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&, const std::error_code&)' 262 | operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e) | ^~~~~~~~ /usr/include/c++/10/system_error:262:5: note: template argument deduction/substitution failed: Non zero exit status: 1