Compilare: main.cpp: In function 'void ins(Nod*&, std::string, int)': main.cpp:21:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | if (k==s.size()-1){ | ~^~~~~~~~~~~~ main.cpp: In function 'void eras(Nod*&, std::string, int)': main.cpp:34:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | if (k==s.size()-1){ | ~^~~~~~~~~~~~ main.cpp: In function 'int query(Nod*, std::string, int)': main.cpp:48:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | if (k==s.size()-1) | ~^~~~~~~~~~~~ main.cpp: In function 'int pref(Nod*, std::string, int)': main.cpp:59:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | if (k==s.size()-1) | ~^~~~~~~~~~~~