Compilare: main.cpp: In member function 'void Trie::add(Trie::Node*&, std::__cxx11::string, int, int)': main.cpp:34:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k == s.size()){ ~~^~~~~~~~~~~ main.cpp: In member function 'int Trie::query(Trie::Node*&, std::__cxx11::string, int)': main.cpp:47:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s.size() == k){ ~~~~~~~~~^~~~ main.cpp: In function 'int main()': main.cpp:69:12: warning: unused variable 'i' [-Wunused-variable] int n, i, cnt = 0; ^