Compilare: main.cpp: In function 'void insert(Trie*, std::string)': main.cpp:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for (int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~ main.cpp: In function 'int search(Trie*, std::string)': main.cpp:41:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | for (int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~ main.cpp: In function 'int longest_prefix(Trie*, std::string)': main.cpp:56:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 56 | for (int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~ main.cpp: In function 'void delete_node(Trie*, std::string)': main.cpp:86:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 86 | for (int i = 0; i < s.length(); i++) | ~~^~~~~~~~~~~~