Compilare: main.cpp: In function 'void add(trie*, std::string&, int)': main.cpp:19:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | if(pos==s.size()) | ~~~^~~~~~~~~~ main.cpp: In function 'bool del(trie*, std::string&, int)': main.cpp:34:11: 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(pos==s.size()) | ~~~^~~~~~~~~~ main.cpp: In function 'int app(trie*, std::string&, int)': main.cpp:56:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 56 | if(pos==s.size()) | ~~~^~~~~~~~~~ main.cpp: In function 'int pref(trie*, std::string&, int)': main.cpp:66:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | if(pos==s.size()) return pos; | ~~~^~~~~~~~~~