Compilare: main.cpp: In function 'void add(node*, std::string, int)': main.cpp:27:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'bool del(node*, std::string, int)': main.cpp:42:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'int query(node*, std::string, int)': main.cpp:71:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | if(i == s.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'int prefx(node*, std::string, int)': main.cpp:80:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | if(i == s.size()){ | ~~^~~~~~~~~~~