Compilare: main.cpp: In function 'void add(node*, std::string, int)': main.cpp:28:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'bool del(node*, std::string, int)': main.cpp:43:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 43 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'int query(node*, std::string, int)': main.cpp:72:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 72 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'int prefx(node*, std::string, int)': main.cpp:81:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 81 | if(i == s.size()){ | ~~^~~~~~~~~~~