Compilare: main.cpp: In member function 'void node::add(const std::string&, const int&)': main.cpp:21:16: warning: comparison of integer expressions of different signedness: 'const int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | if(poz == s.size()){ | ~~~~^~~~~~~~~~~ main.cpp: In member function 'void node::del(const std::string&, const int&)': main.cpp:32:16: warning: comparison of integer expressions of different signedness: 'const int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | if(poz == s.size()){ | ~~~~^~~~~~~~~~~ main.cpp: In member function 'int node::nr_app(const std::string&, const int&)': main.cpp:41:16: warning: comparison of integer expressions of different signedness: 'const int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | if(poz == s.size()){ | ~~~~^~~~~~~~~~~ main.cpp: In member function 'int node::prefix(const std::string&, const int&)': main.cpp:51:16: warning: comparison of integer expressions of different signedness: 'const int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 51 | if(poz == s.size()) { | ~~~~^~~~~~~~~~~